Efficient cartridges make excellent use of their available powder and case/bore capacity. They yield good ballistic performance with relatively little recoil and throat erosion.
Cartridge Efficiency: A Primer (pun intended!)by USAMU Staff
The U.S. Army Marksmanship Unit (USAMU) published a series of reloading articles on its Facebook Page. In this article, the USAMU discusses cartridge case efficiency and its benefits. While this is oriented primarily toward NRA High Power Rifle and Long Range (1000-yard) competition, these factors also apply to medium/big game hunters. Assuming one’s rifle and ammunition are accurate, key considerations include ballistic performance (i.e., resistance to wind effects, plus trajectory), recoil, and throat erosion/barrel life.
Efficient cartridges make excellent use of their available powder and case/bore capacity. They yield good ballistic performance with relatively little recoil and throat erosion. A classic example in the author’s experience involved a featherweight 7x57mm hunting/silhouette rifle. When loaded to modern-rifle pressures, just 43-44 grains of powder pushed a 139gr bullet at 2900 fps from its 22” barrel. Recoil in this light rifle was mild; it was very easy to shoot well, and its performance was superb.
An acquaintance chose a “do everything” 7mm Remington Magnum for use on medium game at short ranges. A larger, heavier rifle, it used ~65 grains of powder to achieve ~3200 fps with similar bullets — from its 26″ barrel. Recoil was higher, and he was sensitive to it, which hampered his shooting ability.
Similarly efficient calibers include the 6mm BR [Norma], and others. Today’s highly-efficient calibers, such as 6mm BR and a host of newer developments might use 28-30 grains of powder to launch a 105-107gr match bullet at speeds approaching the .243 Winchester. The .243 Win needs 40-45 grain charges at the same velocity.
Champion-level Long Range shooters need every ballistic edge feasible. They compete at a level where 1″ more or less drift in a wind change could make the difference between winning and losing. Shooters recognized this early on — the then-new .300 H&H Magnum quickly supplanted the .30-06 at the Wimbledon winner’s circle in the early days.
The .300 Winchester Magnum became popular, but its 190-220gr bullets had their work cut out for them once the 6.5-284 and its streamlined 140-142gr bullets arrived on the scene. The 6.5-284 gives superb accuracy and wind performance with about half the recoil of the big .30 magnums – albeit it is a known barrel-burner.
Currently, the 7mm Remington Short Action Ultra-Magnum (aka 7mm RSAUM), is giving stellar accuracy with cutting-edge, ~180 grain bullets, powder charges in the mid-50 grain range and velocities about 2800+ fps in long barrels. Beyond pure efficiency, the RSAUM’s modern, “short and fat” design helps ensure fine accuracy relative to older, longer cartridge designs of similar performance.
Recent design advances are yielding bullets with here-to-fore unheard-of ballistic efficiency; depending on the cartridge, they can make or break ones decision. Ballistic coefficients (“BC” — a numerical expression of a bullet’s ballistic efficiency) are soaring to new heights, and there are many exciting new avenues to explore.
The ideal choice [involves a] balancing act between bullet BCs, case capacity, velocity, barrel life, and recoil. But, as with new-car decisions, choosing can be half the fun!
Factors to Consider When Evaluating Cartridges
For competitive shooters… pristine accuracy and ballistic performance in the wind are critical. Flat trajectory benefits the hunter who may shoot at long, unknown distances (nowadays, range-finders help). However, this is of much less importance to competitors firing at known distances.
Recoil is an issue, particularly when one fires long strings during competition, and/or multiple strings in a day. Its effects are cumulative; cartridges with medium/heavy recoil can lead to shooter fatigue, disturbance of the shooting position and lower scores.
For hunters, who may only fire a few shots a year, recoil that does not induce flinching during sight-in, practice and hunting is a deciding factor. Depending on their game and ranges, etc., they may accept more recoil than the high-volume High Power or Long Range competitor.
Likewise, throat erosion/barrel life is important to competitive shooters, who fire thousands of rounds in practice and matches, vs. the medium/big game hunter. A cartridge that performs well ballistically with great accuracy, has long barrel life and low recoil is the competitive shooter’s ideal. For the hunter, other factors may weigh more heavily.
Cartridge Efficiency and Energy — Another Perspective
Former Lapua staffer Kevin Thomas explains that efficiency can be evaluated in terms of energy:
“Cartridge efficiency is pretty straight forward — energy in vs. energy out. Most modern single-based propellants run around 178-215 ft/lbs of energy per grain. These figures give the energy potential that you’re loading into the rifle. The resulting kinetic energy transferred to the bullet will give you the efficiency of the round. Most cases operate at around 20-25% efficiency. This is just another way to evaluate the potential of a given cartridge. There’s a big difference between this and simply looking at max velocities produced by various cartridges.”
When shooting at long range, two heads (and two sets of eyes) can be better than one. Teaming up with a buddy who acts as a spotter can speed up your long-range learning process. You can focus 100% on the shot, while your buddy calls the wind and spots your hits and misses.
The NSSF has created a short video that shows how shooter and spotter can work as a team. In the video, the NSSF’s Dave Miles works with Rod Ryan, owner of Storm Mountain Training Center in Elk Garden, WV. As the video shows, team-work can pay off — both during target training sessions and when you’re attempting a long shot on a hunt. Working as a two-person team divides the responsibilities, allowing the shooter to concentrate fully on breaking the perfect shot.
The spotter’s job is to watch the conditions and inform the shooter of needed wind corrections. The shooter can dial windage into his scope, or hold off if he has a suitable reticle. As Rod Ryan explains: “The most important part is for the shooter to be relaxed and… pay attention to nothing more than the shot itself.” The spotter calls the wind, gives the information to the shooter, thus allowing the shooter to concentrate on proper aim, gun handling, and trigger squeeze. Rod says: “The concept is that the spotter does all the looking, seeing and the calculations for [the shooter].”
Spotter Can Call Corrections After Missed Shots
The spotter’s ability to see misses can be as important as his role as a wind-caller. Rod explains: “If you shoot and hit, that’s great. But if you shoot and miss, since the recoil pulse of the firearm is hitting your shoulder pretty good, you’re not going to be able to see where you missed the target. The spotter [can] see exactly where you missed, so I’ll have exactly an idea of how many [inches/mils it takes] to give you a quick secondary call so you can get [back on target].”
Recommended Premium Spotting Scopes
Looking for a truly superior spotting scope? Then check out the Kowa Prominar TSN-880 Series. These big spotters feature ultra-sharp Flourite glass, with huge 88mm front objectives. In comparison tests with other premium spotting scopes the TSN-883 (angled) and TSN-884 (straight) units always finish at or near the top. Right now you can get the TSN-883 (Angled) body at Amazon for $2450.00 or EuroOptic.com for the same price.
At the request of our readers, we provide select “Deals of the Week”. Every Sunday afternoon or Monday morning we offer our Best Bargain selections. Here are some of the best deals on firearms, hardware, reloading components, optics, and shooting accessories. Be aware that sale prices are subject to change, and once clearance inventory is sold, it’s gone for good. You snooze you lose.
NOTE: All listed products are for sale to persons 18 years of age or older. No products are intended for use by minors.
1. Midsouth — Rebate $25-$75 on RCBS Products
⏺ Major RCBS rebate program through 9/20/2023
RCBS recently announced a rebate program that applies to most RCBS products, including presses, powder dispensers, case-prep machines, priming tools, reloading dies and more. You can save up to $75 with this rebate promo. After qualifying purchases, you can submit your rebate request online or by regular mail. Products must be purchased between 8/10/2023 through 9/20/2023, while the deadline for mail-in or online submission is 10/20/2023. CLICK HERE for Rebate ENTRY FORM.
Buy RCBS product(s) totaling between $100 and $249.99 and get $25 back.
Buy RCBS products(s) totaling between $250.00 and $399.99 and get $40 back.
Buy RCBS products(s) totaling $400 or more and get $75 back.
2. Graf & Sons — Major Sale on Primers IN STOCK
⏺ Good selection of primers at very competitive prices
If you need primers, check out the current Primer Sale at Grafs.com. Graf’s has a wide selection of pistol, rifle, and shotshell primers IN STOCK from CCI, Federal, Fiocchi, Remington, and Winchester. But don’t hesitate — the most popular primer types could sell out quickly.
3. Sportsman’s Warehouse — Savage Axis Rifle Sale, $429.99
⏺ Great prices on scope-equipped Savage hunting rifles
Hunters shopping for a new, affordable rifle should consider the Savage Arms Axis XP with Scope now on sale at Sportsman’s Warehouse. For only $429.99 you get the rugged and reliable Savage Arms Axis XP complete with a mounted Bushnell 4-12x40mm scope. The Savage Axis XP features a 22″ button-rifled barrel, 4-round detachable magazine, and black synthetic stock. At the same $429.99 sale price you can get the Axis Compact with 20″ barrel and synthetic stock sized for smaller shooters. There is a wide choice of chamberings: .223 Rem, .243 Win, 6.5 Creedmoor, .270 Win, .308 Win, and .30-06 Springfield.
4. Midsouth — Frankford Arsenal X-10 Press, $999.99
⏺ Save $150 on great, new 10-station progressive press
Midsouth has the impressive new Frankford Arsenal X-10 Progressive Press with Case Feeder on sale for $999.99. Right now you can save $150 and get FREE Shipping. The new X-10 is a 10-station automatic indexing reloading press with strong steel construction, multiple ball bearings, and a proprietary 10-station, gear driven, shell plate. The X-10’s features include dual de-capping stations, in-line primer pocket swaging capability, and the ability to run powder check and case trimming dies. Compared to a Dillon XL750 (or even a $2240 RL1100), the X-10 offers notable additional capabilities and performance.
5. EuroOptic — Vortex Optics Closeouts, Save 47-54%
⏺ Very good deals on popular scopes
Vortex Optics makes excellent optics and Vortex has some of the best customer service in the industry with a rock-solid lifetime guarantee. If you’re looking for a new zoom scope check out the Vortex Optics Sale at EuroOptic.com. You can grab a 3-9x40mm Diamondback, a 4-24x50mm Strike Eagle, and/or 6-24x50mm Viper at 47-54% OFF.
6. Amazon — Highwild AR500 Dueling Tree Target Kit, $179.99
⏺ Fun, six-paddle reactive target at good price
Shooting reactive targets provides instant gratification with a hit. And reactive dueling tree type targets allow a challenging “One on One” competition with a buddy. The Highwild AR500 Dueling Tree Target is a great bargain right now at $179.99. This dueling tree features six reactive paddles made of high-quality, laser-cut AR500 1/4″ thick steel plate. The forward leaning steel post can automatically reset the steel paddles by gravity. That way you don’t need springs or pull-cords.
7. MidwayUSA — Major Ammunition Sale with up to 30% Savings
⏺ Major savings on name brand rifle and pistol ammunition
MidwayUSA is running a big Ammunition Sale right now with very attractive prices. You’ll find 145 types of pistol, rifle, and shotgun ammo for a huge range of cartridges. Among rifle hunting ammo there’s a wide range of bullet choices. Sale prices are up to 30% off. From hunting to target ammo — there’s something for everyone.
8. Amazon — Scope Turret Magnifying Glass with Level, $15.95
Making rapid, yet precise scope turret adjustments can be challenging, especially during fast, timed stages. Most scope turrets have small, thin markings that can be tough to see (particularly with older eyes). To see your elevation turret markings better, try the Monstrum Scope Turret Magnifying Glass with Level. This simple but effective tool places a magnifier on the shooter’s side of the turret allowing easy viewing. In addition, this handy unit includes a built-in bubble level to help the shooter avoid canting his rifle.
9. Amazon — Cordless Air Duster/Vacuum, $49.99 (after discount)
⏺ Very useful for reloading room — with $20 OFF special
Most reloaders use compressed air to clean spilt powder or debris off their work areas because it’s simple and easy. But cans of air are expensive and they loose effectiveness as you use them. A great solution is the iDOO Cordless Air Duster 2-in-1 Vacuum Cleaner. With a powerful brushless motor, the iDOO air duster can blow away dust. Switch the configuration and this dual-purpose unit works as a hand-held vacuum cleaner. NOTE: Amazon’s stated price is $69.99. But there is currently a $20 Off instant coupon. Click the “Apply $20 Coupon” button on the Amazon page to reduce the net price to $49.99.
⏺ Very useful, long-life product that protects your firearms investment
You may own a gunsafe to keep your firearms secure, but do you have a system to protect those firearms from rust and corrosion? Pick up the Hornady Reusable Dehumidifier Bag and you can easily help prevent moisture and rust from ruining your gun collection. This moisture-absorbing bag has a built-in indicator that will change from blue to pink when the pouch is saturated and ready to reactivate.
You’d like to protect your hearing, and maybe you’re a little curious about how your rifle might shoot suppressed. So you’re thinking of buying a suppressor (aka “can”, “moderator”, “silencer”). You can’t just get one off the shelf at Walmart. Acquiring a suppressor requires filling out paperwork and paying a Federal $200 Tax Stamp. Plus there is typically a pretty long wait. However, the good news is that suppressor ownership is now legal in 42 of the 50 American states — that’s 84%! For most American adults, getting a suppressor is legal, provided pass the required background checks.
States Where Suppressor Ownership is Allowed
Currently, the following 42 states allow private ownership of suppressors: AL, AK, AZ, AR, CO, CT, FL, GA, ID, IN, IA, KS, KY, LA, ME, MD, MI, MN, MS, MO, MT, NE, NV, NH, NM, NC, ND, OH, OK, OR, PA, SC, SD, TN, TX, UT, VT, VA, WA, WV, WI, WY.
Note: Even if you live in one of the states listed, you should still verify that owning a suppressor is legal in your area. Some states may have municipal- or county-based restrictions.
States Where Suppressor Ownership is Prohibited
Unfortunately, there are still eight (8) States that forbid private ownership of suppressors. The eight No-Go States are: California, Delaware, Hawaii, Illinois, Massachusetts, New Jersey, New York, Rhode Island. In these eight states, private ownership of suppressors (aka “silencers”) is forbidden. Hopefully that a few of those eight hold-out states will change their laws in the months ahead.
Looking Inside a Suppressor in Action
Popular YouTube Channel Smarter Every Day recently released a cool video featuring rifle suppressors with see-through acrylic sleeves. The team filmed shots through the suppressors using ultra-high-speed (110,000 frame per second) cameras. When played back in super-slow-motion, you can see the flame propagate through the suppressor and the bullet move through each baffle before it exists the muzzle. Watch the results in the video below — it’s mesmerizing:
See Through Suppressor in Super Slow Motion (110,000 fps) — Click Arrow to Watch:
Suppressors, On Average, Reduce Noise Levels about 30 Decibels
In an article for Ammoland, gunwriter Sam Hoober says that you can expect about 30 decibels (dB) of noise reduction from the average suppressor: “Looking at a few different products, SilencerCo attests their suppressors reduce the sound pressure of a 9mm gunshot to anywhere from 125.7 dB to 131.5 dB, depending on the model. Advanced Armament Co, another popular supplier, attests a 23 dB to 33 dB reduction or down to 127 dB. Liberty Suppressors, another manufacturer, attests a reduction of 24 dB to 38 dB, depending on model and other factors. In short, we can presume something on the order of 30 dB of attenuation as an average.”
Using that 30 dB number you can quickly discern that you’ll still need hearing protection — good hearing protection — when shooting any suppressed firearm (even a .22 LR). “Spikes of 130 dB and more can result in permanent hearing damage instantly”. Source: NRA Blog.
Emil Kovan is one of the top F-Class shooters in the world. He won the 2014 United States F-Open Championship, finished second at the 2015 USA Nationals, and then finished second at the 2016 Canadian F-Open Nationals. Most recently Emil was a member of the World Championship-winning F-Open Team USA that competed this spring in South Africa. He definitely knows what it takes to build top-tier F-Open rifles. Today’s feature story first ran a few seasons back, and today there are some more stock and optics options, but this is still a very impressive F-Open rig. To learn more about the latest F-0pen Magnum chambering options read Emil Kovan’s recent Daily Bulletin story, Cartridges for F-Class — Rise of the Magnums.
“What are the best components for an F-Open class rifle, and why?” That’s a question that I get asked all the time and will try to answer in this article. Two months ago, I was contacted by Duane, a gentleman I met at the 2015 F-Class Nationals. He was interested in building a rifle with the impressive Master Class Low Profile F-Open Stock, created by Carl Bernosky and Alex Sitman of Master Class Stocks.
I have known Alex Sitman for many years, and use his stocks exclusively, but was not very familiar with his new Low Profile F-Open stock. After a brief conversation with Alex, I placed an order, and had the stock inletted and bedded at my shop in a month. My first impression was “Wow that’s a long stock” — the forearm is significantly longer than on the original Master Class F-Class prone stock. I bolted the barreled action in, and squeezed the end of the forearm and barrel together, the stock flexed a little bit, but not as much as other designs that I have tested. I think that’s due to having “more meat” in the receiver area. The full stock depth continues farther forward that on some other “low profile” designs. That makes the stock stiffer in the vertical plane, reducing the hinging effect forward of the action. The stock was finished in gloss black per the customer’s request. Interestingly, I found that the multiple layers of paint and clearcoat stiffened the stock up quite a bit.
CLICK IMAGE below for full-screen version
Low Center of Gravity Tames Torque
Compared to the original Master Class F-Open stock, the barrel sits about an inch lower. Lower center of gravity equals less torque, and that is very important when shooting heavy bullets in fast twist barrels. Another significant improvement is that the toe of the stock is flat and parallel to the forearm. I added a 3/4″ track rail in the rear, and milled the underside of the fore-end to create two parallel “rails” in the front to help the stock track better.
One of the biggest reasons why I like Master Class stocks, is the pistol grip. I don’t shoot “free recoil” and a comfortable pistol grip is super important to me when selecting a stock. The new Master Class Low Profile stock shares the same grip as the old model. This allows the stock to accommodate either a “hard hold” style or a more free-recoil style of shooting — whatever the rifle’s owner prefers. This design versatility is one reason I recommend Master Class stocks. Shooters may experiment with either shooting style to find what suits them best.
Cartridge Choice — A 40° .284 Win Improved
Duane decided to have the barrel chambered for my 284 KMR IMP (Improved) wildcat. What is .284 KMR IMP and why choose it over the straight .284 Winchester? Improved by definition means “made better”, I took a great cartridge, and modified it to increase capacity, reduce pressure, and increase brass life.
There are many “improved” variants of the original .284 Winchester: 7mm Walker, .284 Shehane, .284 Ackley and so on. My version, the 284 KMR IMP, shares the .010″ blown-out sidewalls of the .284 Shehane, but I have further increased the case capacity by changing the shoulder angle from 35 to 40 degrees. The 284 KMR IMP allows you to almost match magnum cartridge velocity in a standard-bolt-face action. If you want to run 180gr-class 7mm bullets over 2900 FPS, it is cheaper and more convenient to have a barrel chambered in 284 KMR IMP than to spend $650 for a magnum bolt.
Tuning Loads for the .284 Win Improved Cartridges
The 284 KMR IMP seems to have two nodes, one around 2820 fps and other at 2940 fps. My match load clocks at 2935 fps with single-digit ES. Note –I selected that load based on accuracy, NOT raw speed. A lot of novice (or hard-headed) shooters make the mistake to push their cartridges to the max, and disregard more accurate loads at lower velocity.
The sport of F-Class is rapidly growing, and the equipment used is improving constantly. I remember that only few years ago, an F-Open rifle that could shoot sub-one-inch of vertical at 300 yards was considered competitive. Now, we are pursuing sub-one-inch vertical at 600 yards! It takes a great rifle to approach that goal, but it is also up to the shooter to learn and experiment as much as possible in order to achieve success.
Dies for an Improved .284 Win Cartridge
One of the biggest challenges in campaigning a wildcat cartridge has been obtaining great dies. When searching for custom dies, it almost seems like that the odds are stacked against us. The most common problem is wait-time — custom die orders can take months to be completed. Also, most custom die makers want you to send them two or three cases, each fire-formed three times. I find that funny because if could somehow properly size the cases for three fire-forming cycles, I would not need a sizing die.
Custom-made dies should size the case just right, but sometimes the die’s internal dimensions are slightly off, and this leads to problem number two: dies sizing too much (or even worse) too little. I had a one “custom” die that would not size the bottom of the case enough. This made the extraction of fired cases very difficult. I feel that the best option (if available) for shooters interested in wildcat chambers is to have their gunsmiths make the dies. I offer that die-making service in addition to barrel chambering.
BAT Machine “M” Action
Duane decided to use a BAT M action for this rifle, and I think that he could not have made a better choice. We are blessed with many good match-quality receivers: Barnard, BAT, Borden, Kelbly, Nesika, and Stiller just to mention a few. These are all very well-made and suitable for F-Class. Among BAT Machine Co.actions, I like BAT models M, MB, and 3LL best. I prefer these because because of their size (large bedding footprint) smoothness, timing, options available, and last but not least visual appearance.
Trigger: I recommend and use Jewell triggers. Other good options are: Kelbly, CG Jackson (good 2-Stage) Anschutz (best 2-Stage for Bat and Kelbly actions), Bix’N Andy, and David Tubb.
Barrel: Duane made another good choice here. He decided to go with a Brux 1:8.5″-twist, 4-groove cut-rifled barrel. If you look at the F-Class and Long Range benchrest equipment lists, you will see that cut-rifled barrels are currently dominating. Many records have been shot with both button-rifled, and cut-rifled barrels. I have shot both, and prefer cut-rifled barrels. I am not saying that button-rifled barrels are not capable of shooting as well as cut-rifled barrels, but on average, in my experience, four out of five cut-rifled barrels (from top makers) will shoot well, vs. three out of five buttoned barrels. YMMV, but this is what I’ve observed.
Scope: Duane’s rifle was fitted with a Nightforce 15-55x52mm Competition scope with DDR-2 reticle. This optic is ultra clear, reasonably lightweight (28 oz.), super reliable, and has 1/8 MOA clicks — what you want for long range F-Class competition. In this 15-55X NF model, I like the DDR-2 reticle best, because fine cross hairs (FCH) are hard to see in heavy mirage. The DDR-2 has a heavier horizontal line, with a center dot. March scopes are also very popular and very well-made.
Thanks for reading, and keep ‘em in the middle…
About Emil Kovan Along with being a skilled, respected gunsmith, Emil Kovan has been a very successful F-Class competitor. He was U.S. F-Open National Champion in 2014, and finished second at the U.S. F-Open Nationals in 2015. Most recently he was a member of the World Championship-winning F-Open Team USA that competed this spring in South Africa. He definitely knows what it takes to build top-tier F-Open rifles.
– 2014 F-Class Open National Champion
– 2015 F-Class Open National Championship, Silver Medal
– F-Class Open National Championship Teams, 2015, 2014, 2013, Shooting Team Member
– Over 15 wins in Regional and State Championships in Palma, F-TR, F-Open
– 2013 U.S. National Team Member
– 2023 F-Open Gold Medal Team USA Member, 2023 World Championship in South Africa
BONUS Reading: F-Open Magnum Cartridge Options
Thinking about building a new F-Open rifle? Not sure about the chambering choice ? CLICK HERE to read Emil Kovan’s recent July 2023 article outlining the most popular magnum cartridges for F-Open competition. The .284 Win is still a great option, but bigger magnums do have some advantages.
Burris Signature Rings with polymer inserts are an excellent product. The inserts allow you to clamp your scope securely without ring marks. Moreover, using the matched offset inserts you can “pre-load” your scope to add additional elevation. This helps keep the scope centered in its elevation range while shooting at long range. Additionally, with a -20 insert set in the front and a +20 insert set in the rear, you may be able to zero at very long ranges without using an angled scope base — and that can save money. (To move your point of impact upwards, you lower the front of the scope relative to the bore axis, while raising the rear of the scope.)
Insert Elevation Values and Ring Spacing
People are sometimes confused when they employ the Burris inserts. The inset numbers (-10, +10, -20, +20 etc.) refer to hundredths of inch shim values, rather than to MOA. And you need the correct, matched top/bottom pair of inserts to give you the marked thousandth value. Importantly, the actual amount of elevation you get with Burris inserts will depend BOTH on the insert value AND the spacing between ring centers.
Forum member Gunamonth has explained this in our Shooters’ Forum:
Working with Burris Signature Rings
Burris inserts are [marked] in thousandths of an inch, not MOA. To know how many MOA you gain you also need to know the ring spacing. For example, with a -20 thou insert set in the front and a +20 thou insert set in the rear, if the ring spacing is 6″, the elevation change will be approximately +24 MOA upwards.
Here’s how we calculate that. If you have a 2 X 0.020″ “lift” over a distance of 6 inches (i.e. 0.040″ total offset at 0.5 feet) that’s equivalent to 0.080″ “lift” over 12 inches (one foot). There are 300 feet in 100 yards so we multiply 0.080″ X 300 and get 24″ for the total elevation increase at 100 yard. (Note: One inch at 100 yards isn’t exactly a MOA but it’s fairly close.)
Here’s a formula, with all units in inches:
Total Ring Offset
——————– X 3600 = Change @ 100 yards
Ring Spacing
(.020 + .020)
—————– X 3600 = 24 inches at 100 yards
Ring Spacing: 6 inches
NOTE: Using the above formula, the only time the marked insert offset will equal the actual MOA shift is when the center to center ring spacing is 3.60″. Of course, you are not required to use 3.60″ spacing, but if you have a different spacing your elevation “lift” will be more or less than the values on the inserts.
A good case trimmer is an essential tool for precision hand-loading. To ensure consistent loads, you want your cases to be the exact same length. Today’s Saturday Showcase features five trimming tools, both powered and manually operated, that can trim your sized brass with great precision. In addition, some of these tools will also chamfer case necks inside and out. The powered case trimmers will save you considerable time (and effort) when working will large batches of brass.
Lead photo shows the Henderson Gen 2 trimmer from Panhandle Precision video review.
Henderson Gen 3 Power Trimmer — Ultimate Reloader Review
Gavin Gear of UltimateReloader.com has tested the impressive Henderson Gen 3 (V3) Trimmer. You’ll find a full write-up on Gavin’s website, and you can watch Gavin’s 18.7-minute video review above.
Gavin states: “The Henderson Gen 3 case trimmer is built on an adjustable tri-trim 3-way cutter with different pilots to accommodate different case necks. Three-way cutters trim to length and chamfer the inside and outside all at once. This trimmer has a 1700 RPM spindle and a custom DC motor made in the USA. The Henderson trimmer works much like a milling machine. You do not need much torque because of the way the taper works. The Henderson Gen 3 trimmer delivered outstanding cartridge length consistency after trimming. This trimmer is fast and easy to use and most importantly, returns consistent results.”
CLICK HERE for Henderson Gen 2 Trimmer video review, which shows how to how to set trim length and change cutter heads, using 6.5×47 Lapua, .260 Remington, and .300 Winchester Magnum cases.
Giraud Power Case Trimmer — Full Review by Erik Cortina
In this video, Erik Cortina of CortinaPrecision.com offers some very clever and useful tips that will help you get the most from your Giraud powered case trimmer. The Giraud trimmer is very precise. When set up correctly, it can trim brass with amazing consistency.
In the video, Erik trims 5 pieces of brass in 15 seconds (6:32 mark). He then measures all five with precision calipers (7:00-8:08). All lengths are exact within .0005 (half a thousandth). Erik notes that the Giraud trimmer indexes off the case shoulder. As long as you have fire-formed brass with consistent base-to-shoulder dimensions, you should get very consistent trim lengths.
Lyman Powered Case Trimmer Review
The Lyman Case Trim Xpress is an efficient, precise unit that allows easy adjustment of trim length with a click-adjustable collar. The trimmer comes with a set of cartridge-specific bushings that index off the case shoulder. One nice feature is a variable speed control. For the price, $146.20 on Amazon, this trimmer delivers excellent performance. To see more details, check out F-Class John’s video review of the Lyman Case Trim Xpress which shows set-up and operation.
Frankford Arsenal Universal Case Trimmer (for Power Drills)
This video features a handy tool that attaches to a portable drill. Used with various diameter collets, this can trim most popular sizes of shouldered brass. The universal collet system indexes on case shoulders for precise and consistent trimming (this does NOT work with straight-walled cartridges). The built-in depth micrometer allows for quick and precise micro-adjustments. There is a handy brass shaving ejection port. The system works well, particularly if you can stabilize your power drill in one position. This Frankford Arsenal trimmer, under $65.00 on Amazon, is an affordable alternative to the top-end powered case trimmers. It comes with a handy plastic case that holds the trimmer and collets.
L.E. Wilson Manual Case Trimmer
L.E. Wilson, makers of hand dies, case trimmers and other precision reloading tools, has videos whoe Wilson stainless steel case trimmer with micrometer adjustment (photo below). The first video explains the operation of the Wilson trimmer and shows how to initially assemble the tool, attach the handle, and set the cut length.
This second video shows how to set up the stainless Wilson trimmer with micrometer cut-length control. The micrometer feature allows you to set the cartridge overall trim length with great precision. If you are trimming a variety of different cartridge types, the micrometer cut length control comes in very handy.
BONUS Video: How Important is Consistent Case Length?
This Primal Rights video explains why it is important to maintain precise case lengths if you want best accuracy and most consistent ES/SD. You’ll want to size your cases BEFORE trimming if your trimmer indexes off the case shoulders.
Try a club match this summer! Every summer weekend, there are hundreds of local club “fun matches” conducted around the country. One of the good things about club shoots is that you don’t have to spend a fortune on equipment to have fun. But we’ve seen that many club shooters handicap themselves with a few common equipment oversights or lack of attention to detail while reloading. Here are SIX TIPS that can help you avoid these common mistakes, and build more accurate ammo for your club matches.
1. Align Front Rest and Rear Bag
We see many shooters whose rear bag is angled left or right relative to the bore axis. This can happen when you rush your set-up. But even if you set the gun up carefully, the rear bag can twist due to recoil or the way your arm contacts the bag. After every shot, make sure your rear bag is aligned properly (this is especially important for bag squeezers who may actually pull the bag out of alignment as they squeeze).
Forum member ArtB adds: “To align my front rest and rear bag with the target, I use an old golf club shaft. I run it from my front rest stop through a line that crosses over my speed screw and into the slot between the two ears. I stand behind that set-up and make sure I see a straight line pointing at the target. I also have a piece of tape that I’ve placed on the golf shaft that indicates how far the back end of the rear bag should be placed from the front rest stop.”
2. Avoid Contact Interference
We see three common kinds of contact or mechanical interference that can really hurt accuracy. First, if your stock has front and/or rear sling swivels make sure these do NOT contact the front or rear bags at any point of the gun’s travel. When a sling swivel digs into the front bag that can cause a shot to pop high or low. To avoid this, reposition the rifle so the swivels don’t contact the bags or simply remove the swivels before your match. Second, watch out for the rear of the stock grip area. Make sure this is not resting on the bag as you fire and that it can’t come back to contact the bag during recoil. That lip or edge at the bottom of the grip can cause problems when it contacts the rear bag. Third, watch out for the stud or arm on the front rest that limits forward stock travel. With some rests this is high enough that it can actually contact the barrel. We encountered one shooter recently who was complaining about “vertical flyers” during his match. It turns out his barrel was actually hitting the front stop! With most front rests you can either lower the stop or twist the arm to the left or right so it won’t contact the barrel.
3. Weigh Your Charges — Every One
This may sound obvious, but many folks still rely on a powder measure. Yes we know that most short-range BR shooters throw their charges without weighing, but if you’re going to pre-load for a club match there is no reason NOT to weigh your charges. You may be surprised at how inconsistent your powder measure actually is. One of our testers was recently throwing H4198 charges from a mechanical measure for his 30BR. Each charge was then weighed twice with a Denver Instrument lab scale. Our tester found that thrown charges varied by up to 0.7 grains! And that’s with a premium measure.
4. Measure Your Loaded Ammo — After Bullet Seating
Even if you’ve checked your brass and bullets prior to assembling your ammo, we recommend that you weigh your loaded rounds and measure them from base of case to bullet ogive using a comparator. If you find a round that is “way off” in weight or more than .005″ off your intended base to ogive length, set it aside and use that round for a fouler. (Note: if the weight is off by more than 6 or 7 grains you may want to disassemble the round and check your powder charge.) With premium, pre-sorted bullets, we’ve found that we can keep 95% of loaded rounds within a range of .002″, measuring from base (of case) to ogive. Now, with some lots of bullets, you just can’t keep things within .002″, but you should still measure each loaded match round to ensure you don’t have some cases that are way too short or way too long.
5. Check Your Fasteners
Before a match you need to double-check your scope rings or iron sight mounts to ensure everything is tight. Likewise, you should check the tension on the screws/bolts that hold the action in place. Even with a low-recoiling rimfire rifle, action screws or scope rings can come loose during normal shooting.
6. Make a Checklist and Pack the Night Before
Ever drive 50 miles to a match then discover you have the wrong ammo or that you forgot your bolt? Well, mistakes like that happen to the best of us. You can avoid these oversights (and reduce stress at matches) by making a checklist of all the stuff you need. Organize your firearms, range kit, ammo box, and shooting accessories the night before the match. And, like a good Boy Scout, “be prepared”. Bring a jacket and hat if it might be cold. If you have windflags, bring them (even if you’re not sure the rules allow them). Bring spare batteries, and it’s wise to bring a spare rifle and ammo for it. If you have just one gun, a simple mechanical breakdown (such as a broken firing pin) can ruin your whole weekend.
Here’s a handy new item, particularly if you load large quantities of bulk ammo for a variety of firearms. Lyman’s new Ammo Checkers check the diameters of reloaded rounds and factory ammo, so you can quickly confirm that your ammo fits a standard chamber. Just drop your loaded rounds in the Ammo Checker, and if the round fits into the gauge, it will fit in the gun’s chamber.
Lyman Ammo Checkers are multi-caliber — each orange block checks six or eight different cartridge types, with each caliber/cartridge name engraved on the gauge. Ammo Checkers are machined to SAAMI minimum chamber dimensions from solid blocks of 6061 T6 aluminum. Ammo Checkers are available in three versions covering most common handgun and rifle calibers:
Handgun Ammo Checker (#7833000) $35.99 at Brownells
Fits: 380 Auto, 9mm Luger, 38 Super, 40 S&W, 45 ACP, 38/357, 44 Spl/Mag, and 45 Colt
Why Use a Case Gauge?
We find that case gauges like the Lyman Ammo Checker are particularly useful for handgun reloaders using progressive presses. The chambers of many popular semi-auto pistols are partly unsupported. This allows the case to swell in the bottom quarter. The case may not be sized adequately by your sizing die, which can lead to misfeeds or malfunctions.
Additionally, if you have loaded a large quantity of ammo for a semi-auto rifle such as an AR15, it’s not a bad idea to check your cartridges before you load them into your magazines. All you need is one mis-sized round to cause a stoppage. That will ruin your day if you are competing in a Service Rifle match or 3-Gun event.
The ammunition and reloading component producing divisions of Vista Outdoor will become a new separate company under the name “The Kenetic Group” with NYSE ticker symbol “HUNT”. The Kinetic Group enterprise will make and sell CCI, Federal, Remington (ammunition), Speer, and Hevi-Shot products. The establishment of The Kinetic Group will follow the planned spin-off of Vista Outdoor’s Outdoor Products operations. The Kinetic Group will continue Vista Outdoor’s Sporting Products sales and manufacturing.
Vista Outdoor Inc. (NYSE: VSTO), the parent company of 41 brands that design, manufacture and market sporting and outdoor lifestyle products worldwide, has announced its new name and identity that will be effective following the planned spinoff of Vista Outdoor’s Outdoor Products business.
“The Kinetic Group will be our name moving forward after the separation…” stated Sporting Products President and CEO Jason Vanderbrink. “To hunters and shooters, their favorite brand of ammunition will take center stage as it always has — they’ll look for CCI, Federal, HEVI-Shot, Remington, and Speer on the shelf, at events and online.”
Vista Outdoor will become The Kinetic Group, a name that represents the energy behind the company and its leading ammunition brands. The Kinetic Group will trade on the New York Stock Exchange (NYSO) under the stock ticker “HUNT”, and the brand will feature a North American ram logo. Sporting Products leaders unveiled The Kinetic Group’s branding this week at the CCI-Speer ammunition factory in Lewiston, Idaho.
“The performance of our products is so often measured in energy on target. Kinetic energy is the force behind our world-class brands and exhibits the spirit of the 4,500 American workers who represent our company,” said Vanderbrink, who will be a director on The Kinetic Group’s board of directors post-spin. Joining Vanderbrink on The Kinetic Group’s leadership team are Andy Keegan (CFO) and Jeff Ehrich (General Counsel and Corporate Secretary). Gary McArthur will continue as interim CEO of Vista Outdoor until the completion of the spinoff.
On the new TheKineticGroup.com website, the company explained its company mission:
“Energy is what propels us and inspires us. It defines our products, drives our purpose, and champions our freedoms. Our brands and products give us the ability to unlock freedom, harvest game, protect us, and unite us. Our thirst and our passion to capture and build upon this energy is never extinguished. We are America’s ammunition. We are The Kinetic Group.”
Along with being a skilled, respected gunsmith, Emil Kovan has been a very successful F-Class competitor. He was U.S. F-Open National Champion in 2014, and finished second at the U.S. F-Open Nationals in 2015. Most recently he was a member of the World Championship-winning F-Open Team USA that competed this spring in South Africa. He definitely knows what it takes to build top-tier F-Open rifles.
1. Align Front Rest and Rear Bag
5. Check Your Fasteners
