February 15th, 2018

Shooting on a Spinning Planet — The Coriolis Effect

Whittington Coriolis Effect
Photo by Dustin Ellermann at Whittington Center Range.

The Coriolis Effect comes into play with extreme long-range shots like this (2100 yards at Raton, NM). The rotation of the earth actually moves the target a small distance (in space) during the long duration of the bullet’s flight.

Coriolis Effect Bryan Litz Applied BallisticsWhen you’re out at the range, the Earth seems very stable. But it is actually a big sphere zooming through space while spinning around its axis, one complete turn every 24 hours. The rotation of the earth can create problems for extreme long-range shooters. During extended bullet flight times, the rotation of the planet causes an apparent deflection of the bullet path over very long distances. This is the ballistics manifestation of the Coriolis Effect.

Bryan Litz of Applied Ballistics discusses explains the Coriolis Effect in his Ballistics Books and Seminars. Bryan notes that Coriolis is “a very subtle effect. People like to make more of it than it is because it seems mysterious.” In most common shooting situations inside 1K, Coriolis is not important. At 1000 yards, the Effect represents less than one click (for most cartridge types). Even well past 1000 yards, in windy conditions, the Coriolis Effect may well be “lost in the noise”. But in very calm conditions, when shooting at extreme ranges, Bryan says you can benefit from adjusting your ballistics solution for Coriolis.

Bryan explains: “The Coriolis Effect… has to do with the spin of the earth. You are basically shooting from one point to another on a rotating sphere, in an inertial reference frame. The consequence of that is that, if the flight time of the bullet gets significantly long, the bullet can have an apparent drift from its intended target. The amount [of apparent drift] is very small — it depends on your latitude and azimuth of fire on the planet.”

Coriolis Effect Bryan Litz Applied Ballistics

Coriolis is a very subtle effect. With typical bullet BCs and velocities, you must get to at least 1000 yards before Coriolis amounts to even one click. Accordingly, Bryan advises: “Coriolis Effect is NOT something to think about on moving targets, it is NOT something to think about in high, uncertain wind environments because there are variables that are dominating your uncertainty picture, and the Coriolis will distract you more than the correction is worth.”

“Where you could think about Coriolis, and have it be a major impact on your hit percentage, is if you are shooting at extended range, at relatively small targets, in low-wind conditions. Where you know your muzzle velocity and BC very well, [and there are] pristine conditions, that’s where you’re going to see Coriolis creep in. You’ll receive more refinement and accuracy in your ballistics solutions if you account for Coriolis on those types of shots. But in most practical long-range shooting situations, Coriolis is NOT important. What IS important is to understand is when you should think about it and when you shouldn’t, i.e. when applying it will matter and when it won’t.”

The Coriolis Effect — General Physics
The Coriolis Effect is the apparent deflection of moving objects when the motion is described relative to a rotating reference frame. The Coriolis force acts in a direction perpendicular to the rotation axis and to the velocity of the body in the rotating frame and is proportional to the object’s speed in the rotating frame.

A commonly encountered rotating reference frame is the Earth. The Coriolis effect is caused by the rotation of the Earth and the inertia of the mass experiencing the effect. Because the Earth completes only one rotation per day, the Coriolis force is quite small, and its effects generally become noticeable only for motions occurring over large distances and long periods of time. This force causes moving objects on the surface of the Earth to be deflected to the right (with respect to the direction of travel) in the Northern Hemisphere and to the left in the Southern Hemisphere. The horizontal deflection effect is greater near the poles and smallest at the equator, since the rate of change in the diameter of the circles of latitude when travelling north or south, increases the closer the object is to the poles. (Source: Wikipedia)

Permalink Shooting Skills, Tech Tip 3 Comments »
February 13th, 2018

Tall Target Test — How to Verify Your Scope’s True Click Values

Scope Click Verify Elevation Tall Target Bryan Litz NSSF test turret MOA MIL

Have you recently purchased a new scope? Then you should verify the actual click value of the turrets before you use the optic in competition (or on a long-range hunt). While a scope may have listed click values of 1/4-MOA, 1/8-MOA or 0.1 Mils, the reality may be slightly different. Many scopes have actual click values that are slightly higher or lower than the value claimed by the manufacturer. The small variance adds up when you click through a wide range of elevation.

In this video, Bryan Litz of Applied Ballistics shows how to verify your true click values using a “Tall Target Test”. The idea is to start at the bottom end of a vertical line, and then click up 30 MOA or so. Multiply the number of clicked MOA by 1.047 to get the claimed value in inches. For example, at 100 yards, 30 MOA is exactly 31.41 inches. Then measure the difference in your actual point of impact. If, for example, your point of impact is 33 inches, then you are getting more than the stated MOA with each click (assuming the target is positioned at exactly 100 yards).

Scope Click Verify Elevation Tall Target Bryan Litz NSSF test turret MOA MIL

How to Perform the Tall Target Test
The objective of the tall target test is to insure that your scope is giving you the proper amount of adjustment. For example, when you dial 30 MOA, are you really getting 30 MOA, or are you getting 28.5 or 31.2 MOA? The only way to be sure is to verify, don’t take it for granted! Knowing your scopes true click values insures that you can accurately apply a ballistic solution. In fact, many perceived inaccuracies of long range ballistics solutions are actually caused by the scopes not applying the intended adjustment. In order to verify your scope’s true movement and calculate a correction factor, follow the steps in the Tall Target Worksheet. This worksheet takes you thru the ‘calibration process’ including measuring true range to target and actual POI shift for a given scope adjustment. The goal is to calculate a correction factor that you can apply to a ballistic solution which accounts for the tracking error of your scope. For example, if you find your scope moves 7% more than it should, then you have to apply 7% less than the ballistic solution calls for to hit your target.

CLICK HERE to DOWNLOAD Tall Target Worksheet (PDF) »

NOTE: When doing this test, don’t go for the maximum possible elevation. You don’t want to max out the elevation knob, running it to the top stop. Bryan Litz explains: “It’s good to avoid the extremes of adjustment when doing the tall target test.I don’t know how much different the clicks would be at the edges, but they’re not the same.”

Should You Perform a WIDE Target Test Too?
What about testing your windage clicks the same way, with a WIDE target test? Bryan Litz says that’s not really necessary: “The wide target test isn’t as important for a couple reasons. First, you typically don’t dial nearly as much wind as you do elevation. Second, your dialed windage is a guess to begin with; a moving average that’s different for every shot. Whereas you stand to gain a lot by nailing vertical down to the click, the same is not true of windage. If there’s a 5% error in your scope’s windage tracking, you’d never know it.”

Scope Tall Test level calibrationVerifying Scope Level With Tall Target Test
Bryan says: “While setting up your Tall Target Test, you should also verify that your scope level is mounted and aligned properly. This is critical to insuring that you’ll have a long range horizontal zero when you dial on a bunch of elevation for long range shots. This is a requirement for all kinds of long range shooting. Without a properly-mounted scope level (verified on a Tall Target), you really can’t guarantee your horizontal zero at long range.”

NOTE: For ‘known-distance’ competition, this is the only mandatory part of the tall target test, since slight variations in elevation click-values are not that important once you’re centered “on target” at a known distance.

Permalink Optics, Tech Tip No Comments »
February 11th, 2018

Bullet RPM and Drag — How BC Changes with Bullet Spin Rates

Bryan Litz bullet rpm BC Drag ballistics coefficient twist rate

You may not realize it… but to get the optimum BC from your bullets (i.e. the lowest aerodynamic drag), you must spin the bullets fast enough. Bullet drag increases (as expressed by lower BC) if the bullet spins too slowly. Bryan Litz of Applied Ballistics explains how BC changes with twist rates…

More Spin, Less Drag
In this article, we look at how twist rate and stability affect the Ballistic Coefficient (BC) of a bullet. Again, this topic is covered in detail in the Modern Advancements book. Through our testing, we’ve learned that adequate spin-stabilization is important to achieving the best BC (and lowest drag). In other words, if you don’t spin your bullets fast enough (with sufficient twist rate), the BC of your bullets may be less than optimal. That means, in practical terms, that your bullets drop more quickly and deflect more in the wind (other factors being equal). Spin your bullets faster, and you can optimize your BC for best performance.

Any test that’s designed to study BC effects has to be carefully controlled in the sense that the variables are isolated. To this end, barrels were ordered from a single barrel smith, chambered and headspaced to the same rifle, with the only difference being the twist rate of the barrels. In this test, 3 pairs of barrels were used. In .224 caliber, 1:9” and 1:7” twist. In .243 caliber it was 1:10” and 1:8”, and in .30 caliber it was 1:12” and 1:10”. Other than the twist rates, each pair of barrels was identical in length, contour, and had similar round counts. Here is a barrel rack at the Applied Ballistics Lab:

Applied Ballistics used multiple barrels to study how twist rate affects BC.

stability gyroscopic ballistics coefficient drag twist rate

“The Modern Advancements series is basically a journal of the ongoing R&D efforts of the Applied Ballistics Laboratory. The goal of the series is to share what we’re learning about ballistics so others can benefit.” –Bryan Litz

Barrel twist rate along with velocity, atmospherics, and bullet design all combine to result in a Gyroscopic Stability Factor (SG). It’s the SG that actually correlates to BC. The testing revealed that if you get SG above 1.5, the BC may improve slightly with faster twist (higher SG), but it’s very difficult to see. However, BC drops off very quickly for SGs below 1.5. This can be seen in the figure below from Modern Advancements in Long Range Shooting.

The chart shows that when the Gyroscopic Stability Factor (SG) is above 1.5, BC is mostly constant. But if SG falls below 1.5, BC drops off dramatically.
stability gyroscopic ballistics coefficient drag twist rate

Note that the BC drops by about 3% for every 0.1 that SG falls below 1.5. The data supports a correlation coefficient of 0.87 for this relationship. That means the 3% per 0.1 unit of SG is an accurate trend, but isn’t necessarily exact for every scenario.

It’s a common assumption that if a shooter is seeing great groups and round holes, that he’s seeing the full potential BC of the bullets. These tests did not support that assumption. It’s quite common to shoot very tight groups and have round bullet holes while your BC is compromised by as much as 10% or more. This is probably the most practical and important take-away from this test.

To calculate the SG of your bullets in your rifle, visit the Berger Bullets online stability calculator. This FREE calculator will show you the SG of your bullets, as well as indicate if your BC will be compromised (and by how much) if the SG is below 1.5. With the stated twist rate of your barrel, if your selected bullet shows an SG of 1.5 (or less), the calculator will suggest alternate bullets that will fully stabilize in your rifle. This valuable online resource is based directly on live fire testing. You can use the SG Calculator for free on the web — you don’t need to download software.


Permalink Bullets, Brass, Ammo, Tech Tip 1 Comment »
February 11th, 2018

Range Kit Essentials — 12 Handy Items for Days at the Range

Range Kit Gear shellholder safety dozen essentials

The shooting season is now in full swing. When you head to the range you’ll want to be prepared. That means collecting all the gear you’ll need at the range. It’s easy to forget small, critical items, so we’ve provided a checklist of the small “extras” you should pack before you head out to the range. In addition to rifle, rests, ammo, targets, and cleaning gear, here are a dozen essentials you should include in your range bag.

Shell-Holder — If you don’t have calipers, you can use a shell-holder to check for excessive case expansion from hot loads. If a fired case doesn’t slip into the shell-holder easily, your load is definitely TOO HOT.

Extra Earplugs — Always use ear protection when shooting. We bring a 35mm film canister with extra sets of foam earplugs.

Hex Wrench or Screwdriver for action screws — Action screws can work loose with time. Always bring the appropriate hex wrench or screwdriver whenever you go to the range.

Small Wrench for Scope Rings — Check the tension of your scope base and ring fasteners before you go. Bring along a small Torx wrench for the ring screws (or other tool that fits your fasteners).

Normal and Under-sized Jags — It is often wise to use one-caliber undersize jags when applying solvent with cotton patches. You should have a couple sizes in your range kit.

Extra Batteries — Bring extra batteries for all your electronic gear — which can include chronograph, windmeter, digital camera, GPS etc.

Small Notebook and Pen or Pencil — Use the notebook to record chron data, log group sizes, and make notes about wind and weather conditions.

Adhesive dots — Bring a few sheets of adhesive dots (sold at office supply stores). Use small white or black dots as target pasters. Use larger red or orange dots as aiming points (target centers).

Folding Chair or Camp Stool — This comes in handy if you’re spotting for another shooter, or if you reload away from the firing line.

Water Bottle — You can’t shoot well if you’re dehydrated. Bring at least two quarts of water with you and keep a bottle at the bench.

Surveyors’ Tape and Wood Stakes — You can make inexpensive wind indicators using surveyors’ tape attached to the top of wood stakes.

Small Plastic Ruler — Use this to measure your group sizes. A transparent (see-through) ruler works best. Rulers are also useful for drawing lines on targets.

This list is not intended to be exclusive. There are many other items you may wish to include. Obviously bring safety glasses, and Sharpie-type pens are always handy to mark targets. We invite our readers to add other “essentials” to the list. The important thing is to plan ahead, packing your key items before you drive to the range.

Permalink Gear Review, Tech Tip 1 Comment »
February 10th, 2018

Chrono Report — Using the LabRadar from Bench and Prone

Bart Sauter Ray Gross LabRadar Benchrest Review Chronograph Bench tripod

Bart Sauter of Barts Custom Bullets owns a LabRadar chronograph. He was curious to see how his loads performed in actual match conditions, so he brought his LabRadar to a match and set it up right on his benchtop. What he learned was quite surprising. For one thing, Bart found that tuning for the best accuracy (in the conditions), was NOT simply a matter of maintaining velocity. Read all about Bart’s experience in this AccurateShooter Forum Thread.

Bart has competed in short range Benchrest matches with the LabRadar on the bench! Bart observed: “The benches were quite close, but the LabRadar was able to pick up my shots even with the other guns going off very close to it. This is a pretty impressive piece of gear.” Bart’s LabRadar unit had no trouble picking up shots when set on the bench, a bit behind the muzzle. Bart noted: “Yes it can go a long way back. You can be a lot farther behind the muzzle then advertised. At home I could get back up to around 8 feet and pick up the bullet. It’s more sensitive about the side distance. I had mine on level 4. You can also point it at your buddy’s target and get his velocity.” Bart set his LabRadar to be triggered by the sound of the gun.

RAV battery pack Amazon.comLong-Life Battery Power
Powering the LabRadar at the range is not a problem. Bart used a portable battery pack that can power the LabRadar for a long time: “I bought a RavPower battery pack from Amazon.com. It was the most powerful compact cell phone charger they had and [it costs about $30.00]. It was able to run the LabRadar for two full days without recharging and still had juice.”

The LabRadar is a pretty expensive piece of kit, but there’s nothing else like it on the market. Bart notes: “The LabRadar itself is about $560.00. The stand is $29.95 for the bench mount and the padded carry case is $39.95. So you’re around $630.00 plus shipping.”

High-Quality Portable Base for LabRadar

Labradar Swivel base

If you want to use your LabRadar when shooting prone, there’s a smart new accessory you should consider buying. Matt Owens, one of our Forum members, has created a new, compact base for the LabRadar that works better than the flat, orange baseplate offered by the manufacturer. This $75 folding base is especially useful when shooting prone (see photo above). Matt, aka “Arkcomatt”, explains: “The folding base will fit in the LabRadar case with the unit. No more having to take apart! Just fold the legs. It takes up less room on the bench and allows you to get it closer to the rifle. It is very stable and holds up very well in high winds.” Forum member Peterson1 agrees: “This is more stable than the Labradar base for my use–off a concrete BR bench, yet takes up less space. Also easier/quicker to set unit up and aimed at target. Never take the unit off for transport in LabRadar case.” ORDER BASE HERE.

LabRadar base swivel base chronograph unit

Forum Member SkiUtah02 uses the base with optional spiked feet: “I bought my base with spikes for the feet to put into the ground. I removed the rubber feet, and screwed in the four spiked feet, [and mounted] an old photography lighting stand swivel head to the base! Worked perfectly. Thanks Matt!”

Full LabRadar Field Test/Review by Ray Gross

If you are considering purchasing a LabRadar Chronograph system, we strongly suggest you read the very thorough and informative LabRadar Review by Ray Gross, past Captain of the USA F-TR team.

Bart Sauter Ray Gross LabRadar Benchrest Review Chronograph Bench tripod

Permalink Optics, Tech Tip 1 Comment »
February 10th, 2018

TIP: Polish Seating Stems to Eliminate Ring Marks on Bullets

Seating Stem Reloading Tip Sierra Bullet .223 Remington compressed loads

Here’s a helpful hint for hand-loaders from Sierra Bullets. While this article focuses on Sierra’s new Tipped Match-King bullets, the recommended solutions apply to other bullet types as well. The article explains how sharp edges on a seating stem can cause a ring to be pressed into the bullet jacket — especially with compressed loads that resist downward bullet movement. Here Sierra technician Rich Machholz diagnoses the problem and provides a solution.

Seating Stem Reloading Tip Sierra Bullet .223 Remington compressed loads

Solutions for Ring Marks Caused by Seating Stems

by Sierra Bullets Ballistic Technician Rich Machholz
Now that the new Tipped MatchKing® (TMK) bullets are being shipped and shooters are putting them to use I have received several calls regarding marking on the bullet ogive from the seating stem.

The cause can be traced to one of several things. In the .223 and especially with the long, 77 grain TMK seated at 2.250” or even 2.260” most loads of Varget® and Reloder® 15 are compressed loads, sometimes heavily compressed. This puts a great deal of pressure on the bullet through the seating stem. The result of all this pressure is a mark of varying depth and appearance on the ogive of the bullet. [Editor: We have seen this issue with a variety of other bullet types/shapes as well, including non-tipped VLDs. The solution is profiling the internal cone of the seating stem to match your bullet shape.]

Some older seating stems might even bear against the tip of the bullet which can make a slight bulge in the jacket just below the junction of the resin tip and the copper jacket in a compressed load. If this is the case there is not a ready fix other than calling the die manufacturer and requesting a new deeper seating stem.

Polish Your Seating Stem to Remove Sharp Internal Edges
If the seating stem is of proper depth the culprit most generally is a thin sharp edge on the inside taper of the seating stem. This is an easy fix that can be accomplished by chucking a spare 77 grain bullet in your drill, coating it with valve grinding compound or even rubbing compound or in a pinch even tooth paste.* Remove the seating stem assembly from the seating die. Turn the drill on and put the seating stem recess over the spinning bullet with the polishing compound to break or smooth the sharp edge that is making the offending mark. This might take more than one application to get the proper polish depending upon what you use, but the more you polish the better the blend of angles which will [ensure the stem matches the bullet contours, not leaving a sharp ring].

If the above is a little more than you care to tackle you might try very fine emery cloth twisted to a point that can be inserted into the mouth to the seating stem and rotated to polish the inside to eliminate any sharp edges that might be present.

Load Advice for 77gr TMKs in the .223 Rem
And last but certainly not least. Actually, even though we don’t say you need additional data for the TMKs, remember you are dealing with heavily-compressed loads in some cases because of the additional bullet length. Due to the additional length of these new bullets and in the interest of gaining some room in the case you might consider trying a slightly faster extruded powder like BenchMark or the 4895s or an even more dense powder like the spherical H335®, CFE223 or TAC. The extra room will allow for trouble free bullet seating also.

Good luck and remember we are no further away than your telephone: 1-800-223-8799.

Sierra Bullets Match-King Reloading Bullet Seating

Permalink Bullets, Brass, Ammo, Reloading, Tech Tip 1 Comment »
February 9th, 2018

When and How Scopes Fail — How to Diagnose Optics Problems

Riflescope Repairs

Riflescopes are mechanical contraptions. One of the sad realities about precision shooting is that, sooner or later, you will experience a scope failure. If you’re lucky it won’t happen in the middle of a National-level competition. And hopefully the failure will be dramatic and unmistakable so you won’t spend months trying to isolate the issue. Unfortunately, scope problems can be erratic or hard to diagnose. You may find yourself with unexplained flyers or a slight degradation of accuracy and you won’t know how to diagnose the problem. And when a 1/8th-MOA-click scope starts failing, it may be hard to recognize the fault immediately, because the POI change may be slight.

When An Expensive Scope Goes Bad
A few seasons back, this editor had a major-brand 8-25x50mm scope go bad. How did I know I had a problem? Well the first sign was a wild “drop-down” flyer at a 600-yard match. After shooting a two-target relay, I took a look at my targets. My first 5-shot group had five shots, fairly well centered, in about 2.2″. Pretty good. Everything was operating fine. Then I looked at the second target. My eye was drawn to four shots, all centered in the 10 Ring, measuring about 2.4″. But then I saw the fifth shot. It was a good 18″ low, straight down from the X. And I really mean straight down — if you drew a plumb line down from the center of the X, it would pass almost through the fifth shot.

Is My Scope Actually Malfunctioning or Is This Driver Error?
That was disconcerting, but since I had never had any trouble with this scope before, I assumed it was a load problem (too little powder?), or simple driver error (maybe I flinched or yanked the trigger?). Accordingly, I didn’t do anything about the scope, figuring the problem was me or the load.

Scope Failure mechanical Point of Impact

Even expensive scopes can fail, or start to perform erratically — and that can happen without warning, or for no apparent reason. Here are some signs that you may be having scope issues.

1. Click count has changed signficantly from established zero at known range.
2. Noticeably different click “feel” as you rotate turrets, or turrets feel wobbly.
3. Inability to set Adjustable Objective or side focus to get sharp target image.
4. Shot Point of Impact is completely different than click value after elevation/windage change. For example, when you dial 2 MOA “up” but you observe a 6 MOA rise in POI.

Problems Reappear — Huge POI Swings Affirm This Scope is Toast
But, at the next range session, things went downhill fast. In three shots, I did manage to get on steel at 600, with my normal come-up for that distance. Everything seemed fine. So then I switched to paper. We had a buddy in the pits with a walkie-talkie and he radioed that he couldn’t see any bullet holes in the paper after five shots. My spotter said he thought the bullets were impacting in the dirt, just below the paper. OK, I thought, we’ll add 3 MOA up (12 clicks), and that should raise POI 18″ and I should be on paper, near center. That didn’t work — now the bullets were impacting in the berm ABOVE the target frame. The POI had changed over 48″ (8 MOA). (And no I didn’t click too far — I clicked slowly, counting each click out loud as I adjusted the elevation.) OK, to compensate now I took off 8 clicks which should be 2 MOA or 12″. No joy. The POI dropped about 24″ (4 MOA) and the POI also moved moved 18″ right, to the edge of the target.

Riflescope RepairsFor the next 20 shots, we kept “chasing center” trying to get the gun zeroed at 600 yards. We never did. After burning a lot of ammo, we gave up. Before stowing the gun for the trip home, I dialed back to my 100-yard zero, which is my normal practice (it’s 47 clicks down from 600-yard zero). I immediately noticed that the “feel” of the elevation knob didn’t seem right. Even though I was pretty much in the center of my elevation (I have a +20 MOA scope mount), the clicks felt really tight — as they do when you’re at the very limit of travel. There was a lot of resistance in the clicks and they didn’t seem to move the right amount. And it seemed that I’d have four or five clicks that were “bunched up” with a lot of resistance, and then the next click would have almost no resistance and seem to jump. It’s hard to describe, but it was like winding a spring that erratically moved from tight to very loose.

At this point I announced to my shooting buddies: “I think the scope has taken a dump.” I let one buddy work the elevation knob a bit. “That feels weird,” he said: “the clicks aren’t consistent… first it doesn’t want to move, then the clicks jump too easily.”

Convinced that I had a real problem, the scope was packed up and shipped to the manufacturer. So, was I hallucinating? Was my problem really just driver error? I’ve heard plenty of stories about guys who sent scopes in for repair, only to receive their optics back with a terse note saying: “Scope passed inspection and function test 100%. No repairs needed”. So, was my scope really FUBAR? You bet it was. When the scope came back from the factory, the Repair Record stated that nearly all the internal mechanicals had been replaced or fixed: “Replaced Adjustment Elevation; Replaced Adjustment Windage; Reworked Erector System; Reworked Selector; Reworked Parallax Control.”

How to Diagnose Scope Problems
When you see your groups open up, there’s a very good chance this is due to poor wind-reading, or other “driver error”. But my experience showed me that sometimes scopes do go bad. When your accuracy degrades without any other reasonable explanation, the cause of the problem may well be your optics. Here are some of the “symptoms” of scope troubles:

1. Large shot-to-shot variance in Point of Impact with known accurate loads.
2. Uneven tracking (either vertical or horizontal).
3. Change of Point of Impact does not correspond to click inputs.
4. Inability to zero in reasonable number of shots.
5. Unexpected changes in needed click values (compared to previous come-ups).
6. Visible shift in reticle from center of view.
7. Changed “feel” or resistance when clicking; or uneven click-to-click “feel”.
8. Inability to set parallax to achieve sharpness.
9. Turrets or other controls feel wobbly or loose.
10. Internal scope components rattle when gun is moved.

Source of Problem Unknown, but I Have a Theory
Although my scope came with a slightly canted reticle from the factory, it had otherwise functioned without a hitch for many years. I was able to go back and forth between 100-yard zero and 600-yard zero with perfect repeatability for over five years. I had confidence in that scope. Why did it fail when it did? My theory is side-loading on the turrets. I used to carry the gun in a thick soft case. I recently switched to an aluminum-sided hard case that has pretty dense egg-crate foam inside. I noticed it took some effort to close the case, though it was more than big enough, width-wise, to hold the gun. My thinking is that the foam wasn’t compressing enough, resulting in a side-load on the windage turret when the case was clamped shut. This is just my best guess; it may not be the real source of the problem. Remember, as I explained in the beginning of this story, sometimes scopes — just like any mechanical system — simply stop working for no apparent reason.

Permalink - Articles, Optics, Tech Tip 2 Comments »
February 8th, 2018

6.5 Creedmoor Cut-Down Test — Velocity Per Inch Revealed

Rifleshooter.com 6.5 Creedmoor cut-down test

Rifleshooter.com does some great original research — providing “hard data” you can’t find anywhere else. Here are the eye-opening results of Rifleshooter.com’s 6.5 Creedmoor barrel cut-down test. You may be surprised at the results. Read on…

What do you get when you cut a 6.5 Creedmoor-chambered barrel down to just over 16 inches? A lot more velocity than you might think. Our friends at Rifleshooter.com recently did a barrel cut-down test with 6.5 Creedmoor test rifle, shortening the barrel from 27 to 16.1 inches in one-inch increments. Surprisingly, with a 142gr Sierra MK, the total velocity loss (as measured with a Magnetospeed) was just 158 FPS, an average of 14.4 FPS per inch of barrel length. With the lighter 120gr A-Max bullet, the total velocity loss was 233 FPS, or 21.8 FPS average loss per inch of barrel.

» CLICK HERE to SEE All Velocity Values at All Barrel Lengths

To perform this velocity test, our friend Bill, Rifleshooter.com’s editor, built up a 6.5 Creedmoor rifle using a Remington Model 7 action, 1:8″ twist Green Mountain CM barrel, and MDT LSS Chassis, all obtained from Brownells.com.

Test Procedure
Five (5) rounds of each type of cartridge were fired at each barrel length and the velocity data was recorded with a MagnetoSpeed V3 barrel-mounted chronograph. The rifle was then cleared and the barrel was cut back one inch at a time from 27″ to just over 16″. NOTE: During this winter test, the air temperature was a very chilly 23° F. One would expect higher velocities across the board had the outside temperature been higher.

» Read Full Story with All Test Results at Rifleshooter.com

The photo below shows how the barrel was cut down, inch-by-inch, using a rotary saw. The barrel was pre-scored at inch intervals. As the main purpose of the test was to measure velocity (not accuracy) the testers did not attempt to create perfect crowns.

Rifleshooter.com 6.5 Creedmoor cut-down test

6.5 Creedmoor vs. Other Mid-Sized 6.5mm Cartridges
The 6.5 Creedmoor is a very popular cartridge with the tactical and PRS crowd. This mid-size cartridge offers good ballistics, with less recoil than a .308 Winchester. There’s an excellent selection of 6.5mm bullets, and many good powder choices for this cartridge. When compared to the very accurate 6.5×47 Lapua cartridge, the 6.5 Creedmoor offers similar performance with less expensive brass. For a tactical shooter who must sometimes leave brass on the ground, brass cost is a factor to consider. Here’s a selection of various 6.5mm mid-sized cartridges. Left to right are: 6.5 Grendel, 6.5×47 Lapua, 6.5 Creedmoor with 120gr A-Max, 6.5 Creedmoor with 142gr Sierra MK, and .260 Remington.

6.5 Creedmoor Rifleshooter.com velocity barrel cut cut-down test saw blade

When asked to compare the 6.5 Creedmoor to the 6.5×47 Lapua, Rifleshooter.com’s editor stated: “If you don’t hand load, or are new to precision rifle shooting, get a 6.5 Creedmoor. If you shoot a lot, reload, have more disposable income, and like more esoteric cartridges, get a 6.5×47 Lapua. I am a big fan of the 6.5×47 Lapua. In my personal experience, the 6.5×47 Lapua seems to be slightly more accurate than the 6.5 Creedmoor. I attribute this to the quality of Lapua brass.” Now that Lapua offers 6.5 Creedmoor brass with small primer pockets, the 6.5 Creedmoor is even more attractive.

Permalink Gunsmithing, Tactical, Tech Tip 3 Comments »
February 7th, 2018

Rule Out “Driver Error” — Test Accuracy with Multiple Shooters

When a rifle isn’t shooting up to it’s potential, we need to ask: “Is it the gun or the shooter?” Having multiple shooters test the same rifle in the same conditions with the same load can be very revealing…

When developing a load for a new rifle, one can easily get consumed by all the potential variables — charge weight, seating depth, neck tension, primer options, neck lube, and so on. When you’re fully focused on loading variables, and the results on the target are disappointing, you may quickly assume you need to change your load. But we learned that sometimes the load is just fine — the problem is the trigger puller, or the set-up on the bench.

Here’s an example. A while back we tested two new Savage F-Class rifles, both chambered in 6mmBR. Initial results were promising, but not great — one gun’s owner was getting round groups with shots distributed at 10 o’clock, 2 o’clock, 5 o’clock, 8 o’clock, and none were touching. We could have concluded that the load was no good. But then another shooter sat down behind the rifle and put the next two shots, identical load, through the same hole. Shooter #2 eventually produced a 6-shot group that was a vertical line, with 2 shots in each hole but at three different points of impact. OK, now we can conclude the load needs to be tuned to get rid of the vertical. Right? Wrong. Shooter #3 sat down behind the gun and produced a group that strung horizontally but had almost no vertical.

Hmmm… what gives?

Shooting Styles Created Vertical or Horizontal Dispersion
What was the problem? Well, each of the three shooters had a different way of holding the gun and adjusting the rear bag. Shooter #1, the gun’s owner, used a wrap-around hold with hand and cheek pressure, and he was squeezing the bag. All that contact was moving the shot up, down, left and right. The wrap-around hold produced erratic results.

Shooter #2 was using no cheek pressure, and very slight thumb pressure behind the tang, but he was experimenting with different amounts of bag “squeeze”. His hold eliminated the side push, but variances in squeeze technique and down pressure caused the vertical string. When he kept things constant, the gun put successive shots through the same hole.

Shooter #3 was using heavy cheek pressure. This settled the gun down vertically, but it also side-loaded the rifle. The result was almost no vertical, but this shooting style produced too much horizontal.

A “Second Opinion” Is Always Useful
Conclusion? Before you spend all day fiddling with a load, you might want to adjust your shooting style and see if that affects the group size and shape on the target. Additionally, it is nearly always useful to have another experienced shooter try your rifle. In our test session, each time we changed “drivers”, the way the shots grouped on the target changed significantly. We went from a big round group, to vertical string, to horizontal string.

Interestingly, all three shooters were able to diagnose problems in their shooting styles, and then refine their gun-handling. As a result, in a second session, we all shot that gun better, and the average group size dropped from 0.5-0.6 inches into the threes — with NO changes to the load.

That’s right, we cut group size in half, and we didn’t alter the load one bit. Switching shooters demonstrated that the load was good and the gun was good. The skill of the trigger-puller(s) proved to be the limiting factor in terms of group size.

Permalink Shooting Skills, Tech Tip No Comments »
February 3rd, 2018

Hot Dots — Get Stick-On Circles in All Sizes and Colors

target dots sticker avery label flourescent dot labeloutfitters

Sometimes simpler is better when it comes to targets for fun shooting and load testing. While we normally use test targets from our Downloadable Target Page, it’s sometimes easier to just use brightly-colored “Hi-Viz” adhesive target dots.

Hi-Viz Stick-On Dots in Assorted Colors and Diameters
You can order 1″ target dots in bulk from Labeloutfitters.com. Many colors are available including fluorescent (hi-viz) Red, Green, Orange, and Yellow. These are bright and easy to see even in fading afternoon light. A pack of twenty (20) sheets (1260 dots total) costs just $5.97 (that works out to $4.74 per thousand). For the 1″-diameter stick-on dots you get 63 dots per sheet. Larger, 1.5″-diameter fluorescent dots are also available in 20-sheet packs for $5.97, with 24 large dots per sheet (480 dots total). If you want even bigger, 2″-diameter dots, sheets with 20 Hi-Viz dots per sheet are on sale for $5.97 per 20-pack(400 dots total).

Our friend Danny Reever really likes the bright dots from Label-Outfitters: “Ordered some of the 1″ dots from LabelOutfitters.com and recieved them in two days Priority Mail! Bought the flourescent red,green, and yellow and they are really nice — especially for the price.”

If you prefer smaller, 3/4″-diameter circles, Amazon.com sells Avery packs with 1008 adhesive dots for $2.69 to $6.75 per pack. Colors include Orange ($2.69, item 5465), Neon Red/Orange (item 5467), Neon Yellow (item 5470), Neon Green (item 5468), and Bright Blue (item 5461). We recommend the Neon Red/Orange for most uses, or the Neon Yellow dots for use on a black background. There is even a dispenser-box option with 1000 3/4″ dots on a roll in a box for $9.99. Amazon.com also offers 1″, 1.25″, and 2″-diameter target pasters in 500-dot and 1000-dot rolls. The best deal is a dispenser of 1000 1″ dots for $11.99.

target dots sticker avery label flourescent dot labeloutfitters

Half-Inch Fluorescent Dots for 100-200 Yards
For close-range work, you may prefer 1/2″-diameter dots. Forum member Steve found a source for very small 1/2″ dots: Uline.com. The 1/2″ dots are available in a wide variety of colors including fluorescent Red, Pink, Yellow, and Green. Price is $12.00 for a roll of 1000 dots (item S-2063). Steve notes: “A 1/2″ circle at 300 yards is not quite entirely covered by Nightforce crosshairs at 42-power (I’d say 70% coverage). I.e., it seems easier to line up repeatedly than with the bigger (3/4″) circles, which I used to use. Note that, for me, neon green and neon orange work best on brown cardboard targets. Neon orange works well on white paper.”

Permalink Hot Deals, Tech Tip 1 Comment »
January 30th, 2018

Seven Smart Ways to Use Old Film Canisters

35mm film cannister tip bushings patches

While nearly everybody now favors digital photography over “old-fashioned” 35mm film, don’t toss those old 35mm film canisters, especially the clear Fuji-type with secure snap-in lids. Small plastic film canisters have a multitude of uses for the shooter and reloader.

Here Are Things You Can Do with Plastic Film Canisters:

1. Hold thrown powder charges. If you weigh powder charges after throwing them with a manual powder dispenser, throw the charges first into a film canister and then use that to drop the powder into the measuring pan on your scale. The canister will catch every kernel of powder. If you throw charges directly into a weighing pan, powder can sometimes bounce out. Using the film canister will help keep spilled powder off your loading bench and floor.

2. Store extra sets of foam ear-plugs in the canister. You never want to be without ear protection. This editor has four film canisters filled with plugs. Two go in the range kit, one goes in the car’s glove compartment, and a second stays in a lock box I use to transport pistols. This way I never find myself at the range without ear protection.

3. Place smaller cotton patches in film canisters, marked by caliber. If you use the water-tight Fuji-style canisters, you can even pre-soak the patches with solvent. You can have one canister for wet patches, another for dry patches. That saves time when you’re at the range, and avoids spillage. One caution–some solvents may react with plastic, so test this first before you put a solvent-filled canister in your range kit.

35mm film canister shooting gear rifle kit

4. Store your neck bushings, sorted by caliber in film canisters. With a permanent marking pen, you can mark the side or top of the canister with the bushing sizes, or caliber.

5. Store your favorite Bolt Grease (for rifles) or anti-seize compound (good for pistol slide rails), in the canister. You don’t need to fill it all the way up — a little dab will do ya. We only recommend this with the snap-top Fuji canisters.

6. Protect your muzzles with canisters, during transport. When shipping a rifle or barrel, slip the film canister over the muzzle, then secure it with electrical tape. This will protect the precious crown of a match barrel from dings or damage.

7. Protect front sights with linked film canisters. Forum member SPClark explains: “I’ve seen several shooters use film canisters to make up front match sight protection. Use some elastic cord between two canisters… that’s easy to remove once you get to the line.”

TELL US Your Tips!

There are countless other uses for 35mm film canisters. We invite readers to respond with their own tips on using these handy containers. If you don’t have some stashed in your workshop already, you can get empties for free at most film processing centers. The clear plastic Fuji canisters are the best — you can see what’s inside and the lids are watertight.

Permalink Reloading, Tech Tip 4 Comments »
January 29th, 2018

Carbon Fiber for the Latest Generation of Rifles and Barrels

Sako 85 Carbon Fiber Wolf Hunting Rifle

Gun-makers and barrel builders have adopted aerospace technology, using carbon fiber in their stocks and composite barrels. At SHOT Show 2018, we saw carbon applications on dozens of rifle brands. Some rifles sported full carbon stocks AND carbon-wrapped barrels. Others sported a carbon stock with steel barrel, or a carbon-wrapped barrel in a conventional stock. Carbon is definitely here to stay. This advanced material allows rifles to be lighter yet stronger. The advantages for the hunter in the field are real — a carbon-wrapped barrel can save quite a few pounds. Here are some of the most notable carbon applications we saw at SHOT Show.

Sako 85 Carbon Wolf

Sako 85 Carbon Fiber Wolf Hunting Rifle

Possibly the best-looking carbon-stocked rifle at SHOT Show was the Sako 85 Carbon Wolf, featured in our Top Photo. New for 2018, this rifle features a full carbon composite stock, with the signature carbon fiber weave visible throughout. We found this new-for-2018 rig very ergonomic and nice to handle. The advanced-design RTW carbon fiber stock offers quick, push-button adjustments for comb height and LOP. Though not carbon-wrapped, the conventional 24″ blued steel barrel is fluted, reducing the overall weight of the rifle. Without optics, this rifle weighs well under 8 pounds. We were impressed by the Carbon Wolf, but choked on the steep $3600.00 MSRP. Street price will be lower — EuroOptic.com is listing a $3148.00 price for the Sako 85 Carbon Wolf.

The Firearm Blog says: “The stock features Soft Touch coating. Is is not at all slippery or loud like some carbon stocks can be. The barrels are factory threaded as well. Both the weight and the balance of the Carbon Wolf rifle felt perfect. I may have to add one to my Finnish rifle collection.” This is offered in 6.5 Creedmoor, .308 Win, .30-06 Sprg, 7mm Mag, and .300 Win Mag.

Nosler M48 Long-Range Carbon Rifle

Nosler M48 Long Range Carbon Fiber Hunting Rifle

Nosler recently introduced the M48 Long-Range Carbon rifle with the addition of a PROOF Research, carbon fiber-wrapped, match-grade barrel that significantly reduces the overall weight of the rifle. The carbon-wrapped Proof barrel is mated to a trued M48 receiver and bedded in a Manners MCS-T carbon fiber-strengthened stock. Nosler says: “The Model 48 Long-Range Carbon is an excellent choice for mountain hunting, backcountry excursions and long range competition where weight is a concern.” Initially, this rifle will be offered for 6.5 Creedmoor, 26 Nosler, 28 Nosler, 30 Nosler, .300 Win Mag, and 33 Nosler.

Christensen Arms TFM — Carbon Galore for 7.3-lb Rifle

Christensen Arms TFM Carbon Fiber Hunting Rifle
Christensen Arms TFM Carbon Fiber Hunting Rifle

As you can see there’s a whole lot of carbon fiber in the Christensen Arms TFM rifle. With a carbon-wrapped barrel and full carbon-fiber stock, this handsome rig weighs just 7.3 pounds (short action) or 7.8 pounds (long action). The carbon-wrapped stainless barrel and fully-adjustable Aerograde carbon-fiber stock are mated to a precision-machined action via integrated carbon fiber pillars. In addition, the TFM includes an integrated, 20-MOA optics rail, detachable magazine, and a titanium side-port brake. Impressively, Christensen Arms guarantees 0.5 MOA (half-MOA) accuracy.

Manners Full-Carbon F-Class Stock

Manners F-Class Stock
Manners F-Class Carbon Fiber Stock

For many years now, Manners Composite Stocks has offered an ultra-stiff, Low-Profile ‘Fish Belly’ F-Class Stock. The shell is 100% carbon fiber with a very long, stiff fore-end. From the back of the action to the tip of the fore-end the stock measures 27″ long which is around 7 1/2″ longer than the Manners T4 stock. The idea is to provide a longer wheelbase to better balance the long, 30-32″ barrels favored by many F-Class competitors. The front half of the fore-end is very thin (from top to bottom) to achieve a low profile on the bags. Much thought has gone into controlling fore-end flex. The stock achieves greater vertical rigidity (less deflection under load) through an innovative “fish belly” design. The rounded undersection, like a canoe hull, strengthens the fore-end considerably.

Weatherby Mark V with Carbon-Wrapped Barrel

Weatherby Proof Research Carbon Barrel
Proof Research Carbon-Wrapped Barrel

Weatherby now offers rifles with Proof Research carbon fiber-wrapped barrels. The aerospace-grade carbon fiber in the Mark V Carbon barrel makes the barrel up to 64% lighter than traditional steel barrels of the same contour. Weatherby claims the carbon-fiber technology improves heat dissipation — so the barrel does not heat up as quickly with extended strings of fire. The 26” #4 contour carbon-wrapped barrel has a cut-rifled, hand-lapped 416R grade stainless steel core with a flush thread cap and 5/8-24 muzzle threads. It’s finished in tactical grey Cerakote. The Mark V Carbon carries Weatherby’s SUB-MOA (at 100 yards) accuracy guarantee when used with Weatherby factory or premium ammunition.

Carbon Edge from Fierce Firearms

Proof Research Carbon-Wrapped Barrel

Fierce Firearms also offers a long-range hunting rig with a carbon-wrapped barrel. This is an extremely light rig. Without scope or optional muzzle brake, the short-action version weighs just 6.4 pounds. It is available in Black/gray, Green/black and a variety of Camo finishes including Kryptec Highlander and Typhon patterns. All this lightweight tech doesn’t come cheap. The Carbon Edge retails for $3250.00 and a left-hand version is $250.00 more. Fierce does offer a 0.5 MOA (half-MOA) accuracy guarantee, which is something.

How Good Are Proof Research Barrels? — Commentary by Mike Davis

Over the past 15 years Davis Custom Rifle has installed barrels from most major barrel manufacturers. We are very fortunate to have such quality barrel makers. I think Proof Research falls into that top-of-the-line category. Proof Research carbon-wrapped steel barrels are super light-weight, yet offer rigidity and superb accuracy. I have used them for 22-250, 6mm/6.5mm Creedmoor, .308 Win builds and multiple long range hunting rifles in .280, .280 AI, .300 WSM, .300 Win Mag, 28 Nosler, and 30 Nosler. These builds with Proof Research barrels typically deliver quarter-MOA accuracy or better.

Manners F-Class Carbon Fiber Stock

The Proof Research technology allows us to build lighter rifles with outstanding accuracy, easy cleaning, and the ability to shoot long strings without point of impact shift. It’s not hard to understand why hunting rifles with these capabilities are in high demand. Combined with other light-weight components (such as Titanium actions), it’s not difficult to get these rifles down to 6.25 to 7 pounds total weight before optics.

Permalink Gunsmithing, New Product, Tech Tip 3 Comments »
January 26th, 2018

Toast in Six Seconds — The Brutal Truth of Short Barrel Life

Stopwatch barrel life

This thought-provoking article is one of the 15 most popular Daily Bulletin features over the last 12 months. We are republishing this story today for readers who may have missed it the first time around…

Here’s a little known fact that may startle most readers, even experienced gunsmiths: your barrel wears out in a matter of seconds. The useful life of a typical match barrel, in terms of actual bullet-in-barrel time, is only a few seconds. How can that be, you ask? Well you need to look at the actual time that bullets spend traveling through the bore during the barrel’s useful life. (Hint: it’s not very long).

Bullet-Time-in-Barrel Calculations
If a bullet flies at 3000 fps, it will pass through a 24″ (two-foot) barrel in 1/1500th of a second. If you have a useful barrel life of 3000 rounds, that would translate to just two seconds of actual bullet-in-barrel operating time.

Ah, but it’s not that simple. Your bullet starts at zero velocity and then accelerates as it passes through the bore, so the projectile’s average velocity is not the same as the 3000 fps muzzle velocity. So how long does a centerfire bullet (with 3000 fps MV) typically stay in the bore? The answer is about .002 seconds. This number was calculated by Varmint Al, who is a really smart engineer dude who worked at the Lawrence Livermore Laboratory, a government think tank that develops neutron bombs, fusion reactors and other simple stuff.

On his Barrel Tuner page, Varmint Al figured out that the amount of time a bullet spends in a barrel during firing is under .002 seconds. Al writes: “The approximate time that it takes a 3300 fps muzzle velocity bullet to exit the barrel, assuming a constant acceleration, is 0.0011 seconds. Actual exit times would be longer since the bullet is not under constant acceleration.”

We’ll use the .002 number for our calculations here, knowing that the exact number depends on barrel length and muzzle velocity. But .002 is a good average that errs, if anything, on the side of more barrel operating life rather than less.

So, if a bullet spends .002 seconds in the barrel during each shot, and you get 3000 rounds of accurate barrel life, how much actual firing time does the barrel deliver before it loses accuracy? That’s simple math: 3000 x .002 seconds = 6 seconds.

Stopwatch barrel lifeGone in Six Seconds. Want to Cry Now?
Six seconds. That’s how long your barrel actually functions (in terms of bullet-in-barrel shot time) before it “goes south”. Yes, we know some barrels last longer than 3000 rounds. On the other hand, plenty of .243 Win and 6.5-284 barrels lose accuracy in 1500 rounds or less. If your barrel loses accuracy at the 1500-round mark, then it only worked for three seconds! Of course, if you are shooting a “long-lived” .308 Win that goes 5000 rounds before losing accuracy, then you get a whopping TEN seconds of barrel life. Anyway you look at it, a rifle barrel has very little longevity, when you consider actual firing time.

People already lament the high cost of replacing barrels. Now that you know how short-lived barrels really are, you can complain even louder. Of course our analysis does give you even more of an excuse to buy a nice new Bartlein, Krieger, Shilen etc. barrel for that fine rifle of yours.

Permalink - Articles, Tech Tip 3 Comments »
January 25th, 2018

Primer Performance — Technical Insights by CCI Expert

Primer Priming Tool Magnum primers foil anvil primer construction reloading powder CCI
Winchester Pistol Primers on bench. Photo courtesy UltimateReloader.com.

There is an excellent article about primers on the Shooting Times website. We strongly recommend you read Mysteries And Misconceptions Of The All-Important Primer, written by Allan Jones. Mr. Jones is a bona fide expert — he served as the manager of technical publications for CCI Ammunition and Speer Bullets and Jones authored three editions of the Speer Reloading Manual.

» READ Full Primer “Mysteries and Misconceptions” Article

This authoritative Shooting Times article explains the fine points of primer design and construction. Jones also reveals some little-known facts about primers and he corrects common misconceptions. Here are some highlights from the article:

Primer Priming Tool Magnum primers foil anvil primer construction reloading powder CCISize Matters
Useful Trivia — even though Small Rifle and Small Pistol primer pockets share the same depth specification, Large Rifle and Large Pistol primers do not. The standard pocket for a Large Pistol primer is somewhat shallower than its Large Rifle counterpart, specifically, 0.008 to 0.009 inch less.

Magnum Primers
There are two ways to make a Magnum primer — either use more of the standard chemical mix to provide a longer-burning flame or change the mix to one with more aggressive burn characteristics. Prior to 1989, CCI used the first option in Magnum Rifle primers. After that, we switched to a mix optimized for spherical propellants that produced a 24% increase in flame temperature and a 16% boost in gas volume.

Foiled Again
Most component primers have a little disk of paper between the anvil and the priming mix. It is called “foil paper” not because it’s made of foil but because it replaces the true metal foil used to seal early percussion caps. The reason this little disk exists is strictly a manufacturing convenience. Wet primer pellets are smaller than the inside diameter of the cup when inserted and must be compacted to achieve their proper diameter and height. Without the foil paper, the wet mix would stick to the compaction pins and jam up the assembly process.

Read Full Primer Story on ShootingTimes.com:

Here are two videos that offer some good, basic information on primers:

Permalink - Videos, Reloading, Tech Tip 1 Comment »
January 24th, 2018

Eyeball Your Brass — How to Diagnose Flawed Cases

Case Diagnostics 101 Sierra Bullets .223 Rem 5.56 brass cartridge safety

Ever wondered what caused a particular bulge or marking on a case? And more importantly, does the issue make the case unsafe for further use? Sierra Bullets Ballistic Technician Duane Siercks offers some insight into various issues and their causes in this article from the Sierra Blog.

Incipient Case-Head Separation
This is a Winchester .308 Win case that has a real issue. This case has a very obvious incipient case head separation in the process of becoming a complete failure.

Sierra Case reloading pressure safety inspection

This is most commonly caused by over-sizing the case causing there to be excess headspace on the case. After a few firings and subsequent re-sizing, this case is just about ready to come completely apart. Proper die adjustment is certainly a requirement here. Of course this case is not safe to reuse.

Excessive Pressure (Load Too Hot)
If you will notice in the picture of the case rim, there are two pressure signs to notice. First, look at the primer. It is basically flattened to about the max of what could be considered safe. If this was the only pressure sign noted, I would probably be fine with this load, but would constantly keep an eye on it especially if I was going to use this load in warmer temperatures. This load could easily cross into the “excess pressure” realm very quickly.

Sierra Case reloading pressure safety inspection

There is another sign of pressure that we cannot ignore. If you’ll notice, there is an ejector mark apparent that is located over the “R” of the R-P headstamp. This absolutely tells us that this load would not have been in the safe pressure range. If there were any of these rounds loaded, they should not be fired and should be dis-assembled. This case should not be reloaded.

Split Case-Neck
Here we have an R-P .22-250 case that has died the death. Everything looks fine with this case except the neck is split. This case must be tossed.

Sierra Case reloading pressure safety inspection

A split neck is a normal occurrence that you must watch for. It is caused by work-hardening of the brass. Brass cases get harder with age and use. Brand new cases that are stored for a period of time can become hard enough that they will split like this case within one to two firings. I have had new factory loads do the same thing. Then as we resize and fire these cases repeatedly, they tend to get harder and harder. Eventually they will split. The life of the case can be extended by careful annealing practices. This is an issue that would need to be addressed in an article by itself. Of course this case is no longer usable.

In the classes that I teach, I try to use examples like this to let the students see what they should be looking for. As always, if we can assist you, whether you are new to reloading or very experienced, contact us here at Sierra Bullets by phone at 1-800-223-8799 or by email at sierra@sierrabullets.com.

Dented Case Body
Here we have a Lake City 7.62×51 (.308 Win.) case with two heavy marks/dents in the case body.

Sierra Case reloading pressure safety inspection

This one may be a bit of a mystery. It appears as if this case may have been caught in the action of a semi-auto rifle when the firearm jammed or the case failed to clear during the cycling process. I probably would not reload this case just to prevent any feeding problems. This also appeared to be a factory loaded round and I don’t really see any pressure issues or damage to the case.

CLICK HERE for MORE .223 Rem Case Examples in Sierra Blog

It is very important to observe and inspect your cases before each reloading. After awhile it becomes second nature to notice the little things. Never get complacent as you become more familiar with the reloading process. If ever in doubt, call Sierra’s Techs at 1-800-223-8799.

Sierra Bullets Case Diagnostics Blog

Permalink Bullets, Brass, Ammo, Reloading, Tech Tip No Comments »
January 23rd, 2018

Download Latest Hodgdon IMR Relative Burn Rate Chart

Hodgdon IMR Winchester Burn Rate Powder speed table relative table chart

Hey guys, you’ll probably want to download this new Powder Burn Rate Chart issued by Hodgdon/IMR. This recently-released table includes the latest IMR powders including the Enduron series (IMR 4166, 4451, 4955, 7977), shown in green below. Please note, the chart is not limited to Hodgdon and IMR propellants. It also includes popular powders from Accurate, Alliant, Norma, Ramshot (Western), Vihtavuori, and Winchester.

This chart provides useful information for all hand-loaders. When doing load development, and testing one powder versus another, it’s generally wise to choose propellants that share the same relative burn rate, as least for starters. NOTE: Hodgdon powders are shown in blue, while IMR standard powders are shown in yellow, and Winchester powder are shown in red. DOWNLOAD Chart HERE.


Hodgdon IMR Winchester Burn Rate Powder speed table relative table chart

CLICK HERE to Download Chart as PDF File »

Story find by EdLongrange. We welcome reader submissions.
Permalink Bullets, Brass, Ammo, Reloading, Tech Tip 1 Comment »
January 22nd, 2018

Eye Dominance — Experts Explain How Dominance Affects Vision

6.5 Creedmoor Annealing

6.5 Creedmoor AnnealingThe digital archives of Shooting Sports USA contain many interesting articles. A few seasons back, Shooting Sports USA featured a “must-read” expert Symposium on Eye Dominance, as it affects both rifle and pistol shooting. No matter whether you have normal dominance (i.e. your dominant eye is on the same side as your dominant hand), or if you have cross-dominance, you’ll benefit by reading this excellent article. The physiology and science of eye dominance is explained by Dr. Norman Wong, a noted optometrist. In addition, expert advice is provided by champion shooters such as David Tubb, Lones Wigger, Dennis DeMille, Julie Golob, Jessie Duff, and Phil Hemphill.

EDITOR: We highly recommend you read this article, particularly if you think you may be cross-dominant — meaning your dominant eye is on the opposite side as your dominant hand. For example, this Editor is right-handed, but my left eye is dominant.

Permalink Competition, Tech Tip No Comments »
January 21st, 2018

Pulling Bullets Safely and Efficiently with a Collet Puller

Hornady cam-lock bullet puller ammunition UlimateReloader

When you make a reloading mistake, you may need to “pull down” assembled ammo. The embedded UltimateReloader.com video demonstrates how to use the Hornady Cam-Lock bullet pulling system.

When Reloading Goes Bad — The Danger of Over-Charging
Our friend Gavin Gear of UltimateReloader.com was recently reloading some 9mm pistol ammo with his Hornady progressive press. As part of his reloading procedure, he visually checks the cases — and he noticed that the charges seemed high. Sure enough, his most recently-produced rounds were about two grains over spec. He diagnosed the issue: “I was using a powder measure without a baffle. What happened was, over the course of the loading session, things settled in, and the charge level increased.”

Not knowing just when his powder measure started delivering too much powder, Gavin decided, for safety’s sake, to pull down all the ammo he had just reloaded. Yes that’s time-consuming, but it’s better than the alternative — having a dangerous Kaboom while shooting. With fast-burning pistol powders, a two-grain over-charge could cause a blown case, damaged firearm, and/or serious injury.

Watch Cam-Lock Bullet Puller Used to Remove Bullets from Loaded Ammo:

Use of Bullet Puller starts 4:00 minutes into video.

Gavin says it is vitally important to perform safety checks during the reloading process: “You’ve got to do it — check every single round to make sure there IS powder, and that there’s not too MUCH powder. Double, Triple, Quadruple check your components… and your powder charges. You can’t be too careful.”

To pull down a loaded round, first place the cartridge in the shellholder on your press ram. Then raise the round up into the bullet puller device installed where a die would go. The Hornady Cam-lock bullet puller works by clamping the bullet in a collet when you flip down the red-coated lever. Then, with the case held by the rim in the shell-holder, the bullet exits the cartridge as the press ram is lowered. It takes time, but it’s pretty fool-proof once you get the hang of it. This entire process is illustrated in Gavin’s video, starting near the four-minute mark.

Hornady Cam-Lock Bullet puller Gavin Gear Ultimate Reloder.com

The Hornady Cam Lock Bullet Puller has four (4) key components: 1. Cam-Lock die body; 2. Cam-Lock lever; 3. Stem; and 4. Collet (Caliber-specific).

NOTE: In order to use this tool, you’ll need the appropriate collet for each diameter range of bullets you intend to pull. For example use collet #3 for 6mm, collect #6 for 7mm, and collet #7 for .308 Caliber.

Hornady cam-lock bullet puller ammunition UlimateReloader

Permalink - Videos, Reloading, Tech Tip 1 Comment »
January 20th, 2018

RCBS Lock-Out Die Helps Prevent Faulty Charges on Progressives

RCBS Lock-out dieIf you load pistol or rifle ammo with a progressive press, we strongly recommend you get a Lock-Out Die from RCBS. This unique reloading die will prevent your progressive press from advancing if the dispensed powder charge is more or less than about 0.3 grains too high or too low. The Lock-Out Die really works. Your Editor uses it on his RCBS 2000 progressive press. I can affirm that a Lock-Out Die has “saved my bacon” a half-dozen times over the years when there was an over-charge (which could cause a Kaboom) or a low charge (which could cause a squib load).

The Lock-Out Die works by using a central die detection rod that sets its vertical position based on the height of the powder column in the case. Through an ingenious design, if the powder column height is too low or too high, the rod locks in place as you start to pull the press handle. This halts the press before the ram can lift and the cartridge plate can advance. Unlike a beeping alarm system (which can be ignored or defeated), the Lock-Out Die physically stops the movement of the press ram and prevents a bullet being seated in the “problem” case.

RCBS Lock-out dieIt takes a bit of tweaking to get the Lock-Out Die detection rod setting just right, but once it is correctly positioned, the Lock-Out Die works smoothly in the background. The Lock-Out Die won’t interfere with the loading process unless it detects a high or low charge — and then it positively stops the progressive loading cycle.

While crafted for use in RCBS progressive presses, the RCBS Lock-Out Die can also be used on a Dillon XL Progressive (see video below) or Hornady Lock-N-Load progressive — though it does take up one station which could otherwise be used for a final crimp die (after the seating die). The RCBS 2000 has one more station than a Dillon 550/650, so it’s an ideal platform for using the Lock-Out Die.

Learn More at UltimateReloader.com
On the UltimateReloader.com website, run by our friend Gavin, you’ll find an excellent two-part series on the function and set-up of the RCBS Lock-Out Die. Part One explains how the Lock-Out Die functions, using cut-away illustrations. Part Two shows how to install and adjust the Lock-Out Die on various progressive presses. The video below shows setup of the RCBS Lock-Out Die on the Dillon XL-650 progressive press.

Images © 2011 UltimateReloader.com, used by permission.
Permalink Reloading, Tech Tip No Comments »
January 20th, 2018

Five Great Tech Articles: Bedding, Target Software, Case Prep, Action Torque, Stock Painting

Technical Article AccurateShooter OnTarget, Stock painting, Pillar Bedding

AccurateShooter.comReaders who have just recently discovered the Daily Bulletin may not realize that AccurateShooter.com has hundreds of reference articles in our archives. These authoritative articles are divided into mutiple categories, so you can easily view stories by topic (such as competition, tactical, rimfire, optics, shooting skills etc.). One of the most popular categories is our Technical Articles Collection. On a handy index page (with thumbnails for every story), you’ll find over 100 articles covering technical and gunsmithing topics. These articles can help you with major projects (such as stock painting), and they can also help you build more accurate ammo. Here are five popular selections from our Technical Articles archive.

pillar Bedding

Stress-Free Pillar Bedding.
Richard Franklin explains how to do a top-quality bedding job, start to finish.

On Target Software Review

OnTarget Software Review.
Our Editors test free software that measures shot groups with great precision. We explain how to use the program and configure advanced features.

Savage Action Tuning Torque Settings

Savage Action Tuning.
Top F-TR shooter Stan Pate explains how to enhance the performance of your Savage rifle by optimizing the torque settings of the action screws.

Precision Case Prep for Reloading

Complete Precision Case Prep.
Jake Gottfredson covers the complete case prep process, including brass weight sorting, case trimming, primer pocket uniforming, neck-sizing, and, case-neck turning.

rifle stock painting and spraying

Stock Painting Instructions.
Step-by-step guide for stock painting by expert Mike Ricklefs. Mike shows both simple coverage and fancy effects.

Permalink - Articles, Gunsmithing, Tech Tip No Comments »