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December 17th, 2015
Butch Lambert of ShadeTree Engineering provided this tip. Butch notes that many 6 PPC benchrest group shooters also enjoy shooting in score matches. But to be really competitive in the BR for score game, that means shooting a 30BR, which has a wider, .308-class rim (0.4728″ diameter). Likewise, if you want to compete in 600-yard registered BR events or in varmint matches, you probably want to run a bigger case, such as the 6BR, 6mm Dasher, or 6-6.5×47. Those cartridges also have the larger 0.4728″ rims.
To convert a PPC-boltface action to shoot the bigger cases you can spend a ton of money and buy a new bolt. That can cost hundreds of dollars. The simpler solution is to turn down the diameter of the larger cases on a lathe. Butch explains: “We’ve seen plenty of interest in rebating case rims. This lets you shoot a 30BR in score matches using your PPC action. All you need is a new barrel. This saves buying another bolt, receiver, or rifle if you have a PPC boltface. Anyone who has access to a lathe can do this job pretty easily. Yesterday I turned 150 case in about an hour.” Below are photos of a rebated 6BR case, along with the lathe form tool Butch uses to rebate the case rims.
Cutting Head for Rebating Rims
December 3rd, 2015
Six bucks — that’s less than the price of a burger and fries these days. But for the same small sum you can get something that will last a lot longer — a Sierra Counter Mat that displays the entire line of Sierra Bullets from .20 caliber up to .458 caliber. Right now Sierra is offering its foam-backed 16 ¼” x 21 ½” counter mat for just $6.00 (plus S&H). This displays over 160 bullet types (including 10 new bullets), complete with specifications, BCs and product codes. You can order online from the Sierra website or call 1-888-223-3006. Note, the last shipping day for 2015 will be Friday, December 18th.
This is a handy item for your reloading room or workshop. The mat provides a comfortable, non-marring surface for working on your rifles and pistols. It will also, to some degree, provide a barrier to oils and solvents, protecting your bench top.
November 12th, 2015
IMR just announced its latest Enduron powder, IMR 4955, which features a medium-slow burn rate similar to Hodgdon H4831 or IMR 4831. The IMR Enduron powders are clean-burning, temp stable, and feature a proprietary coating that helps reduce copper fouling. We are looking forward to trying IMR 4955 based on our positive experience with IMR 4166. We have used Enduron 4166 and have seen excellent accuracy in .308 Winchester and 6mm BR rifles.
IMR 4955 lands between IMR 4451 and IMR 7977 on the burn rate chart. Hodgdon, which distributes IMR powders, says that IMR 4955 works very well for cartridges such as 25-06 Remington, .270 Winchester, and the .300 Winchester Magnum. Perhaps this will prove a good choice for the .284 Win and .300 WSM as well (F-Open shooters take note). If you are currently using H4831 or H4831sc you should probably give IMR 4955 a try.
Hodgdon says IMR 4955 offers some important advantages:
1. IMR 4955 has a small kernel size. This allows the powder to flow through powder measures easily and meter very accurately.
3. IMR 4955 is very insensitive to temperature changes, so shooters should see uniform velocities across a broad temp range.
3. IMR 4955 has very good load density for medium and big game hunting cartridges (such as the .270 Win and .300 Win Mag).
4. Like other Enduron powders, IMR 4955 boasts a special additive that helps reduce copper fouling as the rifle is fired.
 IMR 4955 Should Be Available Early Next Year
— Load Data is Online Now
IMR 4955 will be available in early 2016 in one-pound and eight-pound containers. With the addition of IMR 4955 to the series of Enduron powders, reloaders have a new, advanced-formulation powder that should work for a wide variety of popular cartridges — from the .260 Rem up to big magnums. Reloading data for IMR 4955 is now available online in the Hodgdon Reloading Data Center. Below is a sample of Hodgdon/IMR load data for IMR 4955 as used in the .300 Win Mag cartridge.
November 3rd, 2015
Do you own an RCBS electronic powder dispenser? If you do, take the time to watch this ChargeMaster Tuning video from 8541 Tactical. This nine-minute video demonstrates how to re-program your Chargemaster to “tune” the dispensing process. The video shows the exact programming procedures to follow, step-by-step. Some folks want a faster powder flow — others tune their machines for a more reliable drop (with fewer over-runs). One cheap and popular modification is to insert a 1″-long section of a McDonald’s straw in the ChargeMaster’s silver dispensing tube. This works surprisingly well to smooth kernel drop and prevent “clumping” that can cause an over-charge. The McDonald’s straw MOD is demonstrated in this video, starting at the 6:22 mark.
Large-Diameter Dispensing Tube Mod
Many folks have had success with the McDonald’s straw modification demonstrated in the above video. However, some folks would like to get even better flow performance (with virtually no clumping). Forum Member Frank B. has come up with a new option using a brass hose fitting with a large outside diameter. The hose fitting (with tape wrapped around the barbed nose section) is placed inside the RCBS dispensing tube (be sure to have some kind of wrap — you don’t want metal-on-metal). Here’s how the unit looks installed:
Frank tells us: “I have found a cure for the over-throw problem. It is a simple 1/4″ barbed hose nipple. I wrapped a couple layers of tape around the barbed end for a snug fit. With this in place, I have thrown 100+ charges of Varget without a single overthrow. The ID of the barbed end needs to be approximately 3/16″ to feed a steady flow. This works because of the larger ID at the drop.”
Frank adds: “You can see in the photo that the powder is not stacking up. You can watch it drop one grain at a time. Hope this will take the aggravation out of your case charging.” For best performance with this brass fitting MOD, we recommend de-burring and smoothing out the front edge of the brass fitting over which the kernels drop.
Brass fitting mod suggested by Boyd Allen. We welcome reader submissions.
November 1st, 2015
21st Century Shooting produces a high quality powder funnel, that is very “user-friendly”. The top section is precision ground and polished for a smooth flow. The center has a see-through tube so you can watch the progress of your powder dropping into the case. At the bottom of each funnel is a black case adapter that seats securely yet won’t get stuck on the case. There are five different adapter sizes — the smallest fits .17 Rem to .223 Rem, while the largest fits big magnum calibers. We use the mid-sized, #3 adapter most often. This fits 6mmBR, 6.5×47 Lapua, and .308 Win family of cases (.243 Win, .260 Rem, 7mm-08, .308 Win). Additional adapters are $5.99 each. There are three tube lengths available: 3″, 6″, and 10″. So, if you need an extra-long drop tube (to help fill PPC and other small cases), 21st Century has you covered.
 The 21st Century funnels are priced by size. The 3″-long model is $29.99, the 6″-long model is $31.99, and the big 10″-long model is $34.99. Prices include one (1) adapter. These high-grade funnels will help you load faster and easier, with fewer spilled kernels. We use these funnels and they do work well. The appropriate collars fit your .223 Rem, 6PPC, 6mmBR, Dasher, 6XC, .260 Rem, .284 Win, and .308 case necks just right — not too loose, not too tight. Kernels flow smoothly through the tube without sticking to the sides. The aluminum top section does not seem to attract a static charge so you don’t have to waste time brushing kernels off the funnel after use. We like this product. For high-volume precision reloaders, these funnels are worth the money.
October 6th, 2015
When your cases become hard to extract, or you feel a stiff bolt lift when removing a cartridge, it’s probably time to full-length size your cases, and “bump” the shoulder back. With a hunting load, shoulder bumping may only be required every 4-5 loading cycles. Short-range benchrest shooters, running higher pressures, typically full-length size every load cycle, bumping the shoulder .001-.002″. High Power shooters with gas guns generally full-length size every time, and may need to bump the shoulders .003″ or more to ensure reliable feeding and extraction.
Use Shims for Precise Control of Shoulder Bump
Some shooters like to set the “default” position for their full-length die to have an “ample” .003″ or .004″ shoulder bump. When they need less bump, a simple way to reduce the amount of shoulder movement is to use precision shims in .001″ (one-thousandth) increments.
Here are reports from Forum members who use the shims:
“Great product. I have my die lock ring(s) adjusted for the shortest headspace length on my multiple chambers 6BRs and 6PPCs. When needing a longer headspace, I just refer to my notes and add the appropriate shim under the lock ring. Keep it simple.” — F.D. Shuster
Mats Johansson writes: “I’ve been using [shims] since Skip Otto (of BR fame) came out with them. I set up my dies with the .006″ shim, giving me the option of bumping the shoulder a bit more when the brass gets old and hardens while still having room to adjust up for zero headspace, should I have missed the original setup by a thou or two. Hunting rounds can easily be bumped an extra .002-.003″ for positive, no-crush feeding. Being a safety-oriented cheapskate, I couldn’t live without them — they let me reload my cases a gazillion times without dangerous web-stretching. Shims are a must-have, as simple as that.” — Mats Johansson
 Sinclair Int’l offers a seven-piece set of Sizing Die Shims that let you adjust the height of your die (and thereby the amount of bump and sizing) in precise .001″ increments. Sinclair explains: “Some handloaders will set their die up to achieve maximum sizing and then progressively use Sinclair Die Shims between the lock ring and the press head to move the die away from the shellholder. Doing this allows you to leave the lock ring in the same position. These shims are usually available in increments of .001″ and work very well.”
Seven Shims from .003″ to .010″
Sinclair’s $12.49 Die Shim Kit (item 22400) includes seven shims in thicknesses of .003, .004, .005, .006, .007, .008, and .010. For ease of use, shim thickness is indicated by the number of notches cut in the outer edge of each shim. Even without looking you can “count” the notches by feel.
September 27th, 2015
Image by ModernArms, Creative Common License.
by Philip Mahin, Sierra Bullets Ballistic Technician
This article first appeared in the Sierra Bullets Blog
The ANSI / SAAMI group, short for “American National Standard Institute” and “Sporting Arms and Ammunition Manufacturers’ Institute”, have made available some time back the voluntary industry performance standards for pressure and velocity of centerfire rifle sporting ammunition for the use of commercial manufacturers. [These standards for] individual cartridges [include] the velocity on the basis of the nominal mean velocity from each, the maximum average pressure (MAP) for each, and cartridge and chamber drawings with dimensions included. The cartridge drawings can be seen by searching the internet and using the phrase ‘308 SAAMI’ will get you the .308 Winchester in PDF form. What I really wanted to discuss today was the differences between the two accepted methods of obtaining pressure listings. The Pounds per Square Inch (PSI) and the older Copper Units of Pressure (CUP) version can both be found in the PDF pamphlet.
 CUP Pressure Measurement
The CUP system uses a copper crush cylinder which is compressed by a piston fitted to a piston hole into the chamber of the test barrel. Pressure generated by the burning propellant causes the piston to move and compress the copper cylinder. This will give it a specific measurable size that can be compared to a set standard. At right is a photo of a case that was used in this method and you can see the ring left by the piston hole.
PSI Pressure Measurement
What the book lists as the preferred method is the PSI (pounds per square inch or, more accurately, pound-force per square inch) version using a piezoelectric transducer system with the transducer flush mounted in the chamber of the test barrel. Pressure developed by the burning propellant pushes on the transducer through the case wall causing it to deflect and make a measurable electric charge.
Q: Is there a standardized correlation or mathematical conversion ratio between CUP and PSI values?
Mahin: As far as I can tell (and anyone else can tell me) … there is no [standard conversion ratio or] correlation between them. An example of this is the .223 Remington cartridge that lists a MAP of 52,000 CUP / 55,000 PSI but a .308 Winchester lists a 52,000 CUP / 62,000 PSI and a 30-30 lists a 38,000 CUP / 42,000 PSI. It leaves me scratching my head also but it is what it is. The two different methods will show up in listed powder data[.]
So the question on most of your minds is what does my favorite pet load give for pressure? The truth is the only way to know for sure is to get the specialized equipment and test your own components but this is going to be way out of reach for the average shooter, myself included. The reality is that as long as you are using printed data and working up from a safe start load within it, you should be under the listed MAP and have no reason for concern. Being specific in your components and going to the load data representing the bullet from a specific cartridge will help get you safe accuracy. [With a .308 Winchester] if you are to use the 1% rule and work up [from a starting load] in 0.4 grain increments, you should be able to find an accuracy load that will suit your needs without seeing pressure signs doing it. This is a key to component longevity and is the same thing we advise [via our customer service lines] every day. Till next time, be safe and enjoy your shooting.
September 12th, 2015
Each Wednesday, the U.S. Army Marksmanship Unit publishes a reloading “how-to” article on the USAMU Facebook page. This week’s “Handloading Hump Day” post covers an important safety issue — why you should never assume that a stated “book” load for a particular bullet will be safe with an equal-weight bullet of different shape/design. The shape and bearing surface of the bullet will affect the pressure generated inside the barrel. Visit the USAMU Facebook page next Wednesday for the next installment.
Beginning Handloading, Part 13:
Extrapolating Beyond Your Data, or … “I Don’t Know, What I Don’t Know!”
Last week, we addressed several key facets of Service Rifle reloading. Today, we continue our Handloading Safety theme, focusing on not inadvertently exceeding the boundaries of known, safe data. Bullet manufacturers’ loading manuals often display three, four, or more similar-weight bullets grouped together with one set of load recipes. The manufacturer has tested these bullets and developed safe data for that group. However, seeing data in this format can tempt loaders — especially new ones — to think that ALL bullets of a given weight and caliber can interchangeably use the same load data. Actually, not so much.
The researchers ensure their data is safe with the bullet yielding the highest pressure. Thus, all others in that group should produce equal or less pressure, and they are safe using this data.
However, bullet designs include many variables such as different bearing surface lengths, hardness, and even slight variations in diameter. These can occasionally range up to 0.001” by design. Thus, choosing untested bullets of the same weight and caliber, and using them with data not developed for them can yield excess pressures.
This is only one of the countless reasons not to begin at or very near the highest pressure loads during load development. Always begin at the starting load and look for pressure signs as one increases powder charges.
Bullet bearing surface length (BSL) is often overlooked when considering maximum safe powder charges and pressures. In photo 1 (below), note the differences in the bullets’ appearance. All three are 7mm, and their maximum weight difference is just five grains. Yet, the traditional round nose, flat base design on the left appears to have much more BSL than the sleeker match bullets. All things being equal, based on appearance, the RN/FB bullet seems likely to reach maximum pressure with significantly less powder than the other two designs.
Photo 1: Three Near-Equal-Weight 7mm Bullets with Different Shapes
Due to time constraints, the writer used an approximate, direct measurement approach to assess the bullets’ different BSLs. While fairly repeatable, the results were far from ballistics engineer-grade. Still, they are adequate for this example.
Bullet 1 (L-R), the RN/FB, has a very slight taper and only reaches its full diameter (0.284”) very near the cannelure. This taper is often seen on similar bullets — it helps reduce pressures with good accuracy. The calculated BSL of Bullet 1 was ~0.324”. The BSL of Bullet 2, in the center, was ~0.430”, and Bullet 3’s was ~ 0.463”. Obviously, bullets can be visually deceiving as to BSL!
Some might be tempted to use a bullet ogive comparator (or two) to measure bullets’ true BSL for comparison’s sake. Unfortunately, comparators don’t typically measure maximum bullet diameter and this approach can be deceiving.
Photo 2: The Perils of Measuring Bearing Surface Length with Comparators
In Photo 2, two 7mm comparators have been installed on a dial caliper in an attempt to measure BSL. Using this approach, the BSLs differed sharply from the original [measurements]. The comparator-measured Bullet 1 BSL was 0.694” vs. 0.324” (original), Bullet 2 was 0.601” (comparator) vs. 0.430” (original), and Bullet 3 (shown in Photo 2) was 0.602” (comparator) vs. 0.463” (original). [Editor’s comment — Note the very large difference for Bullet 1, masking the fact that the true full diameter on this bullet starts very far back.]
Please join us again next week as we examine other lesser-discussed variables that affect pressure and velocity during handload development. In the meantime, stay safe, and favor center!
September 5th, 2015
German Salazar has written a very thorough guide to measuring nearly all the critical dimensions of cartridge brass. In his Measuring the Case article, on his Rifleman’s Journal website, German reviews the tools and techniques required to measure everything from case overall length to case neck concentricity. Step-by-step, German shows how to measure: Case Length, Case Body length (below neck), Neck Diameter, Headspace, Base Diameter, Neck Thickness, and Case Neck Concentricity.
If you are an “advanced reloader” or want to be, you should read German’s article. Not only does German explain the most common measuring procedures, he highlights some alternative methods you might not have tried yet. The article also links to related discussions of more complex measurement tasts, such as determining case body wall thickness variation.
Even if you’re not a competitive shooter, measuring your brass can provide important safety benefits. As German explains in the conclusion of his article: “There are obviously a lot of measurements that can be taken on the cartridge case and in some cases, more than one way to take them. However, the first two that any new reloader must learn are case length and neck clearance, these two are safety concerns and if overlooked can results in serious damage to the rifle and injury to you.”
German’s article first appeared in RiflemansJournal.com in 2010.
August 10th, 2015
 Harrell’s Precision sells “semi-custom” full-length bushing dies for the PPC and 6BR chamberings. While the Harrell brothers do not cut the die to spec, they carry a large selection of dies made with slightly different internal dimensions. When you send in your fired brass, the Harrells choose a die from inventory with just the right amount of sizing (diameter reduction) at the top and bottom of the case. Given the quality, and precise fit, Harrell’s full-length dies are a good value at $70.00 plus shipping.
 Bump Measuring Collar
The Harrell brothers provide a nice bonus item with each full-length die — a neat, little shoulder bump measuring device as shown in the photo at right. Hornady/Stoney Point sells a stand-alone tool that does the same job, but the Harrell’s bump collar is simpler and faster. To measure your shoulder bump, simply place the Harrell’s bump collar over the front of your deprimed case (before sizing) and measure the OAL with your calipers. Then size the case in your full-length die, replace the collar and repeat the measurement. You want to set your die so the shoulder moves back about .001″ to .0015″ for most applications. (With semi-auto guns you may want more bump.)
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