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August 31st, 2016
Emil Kovan is one of the top F-Class shooters in the world. He won the 2014 United States F-Open Championship. Earlier this month Emil finished second in F-Open Division at the 2016 Canadian National F-Class Championship in Ontario. Emil actually tied Open-class winner Shiraz Balolia for overall score AND “V”-count, but Emil was awarded second on the tie-breaker.
The Anatomy of a Modern F-Class Open Rifle
Report by Emil Kovan
Kovan Match Rifles LLC, www.matchrifles.com
“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 new 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.
Brux Barrels is not the only company that produces very accurate cut-rifled barrels. We know that Krieger, Bartlein, Satern, and Hawk Hill Custom all make fine cut-rifled barrels as well.
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…
 Emil Kovan Competition History:
– 2014 F-Class Open National Champion
– 2016 F-Class Open Canadian Championship, Silver Medal (tied for first on score)
– 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
– 2017 U.S. National Development Team Member
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August 30th, 2016
Could your gun club or youth shooting group use money to upgrade range facilities or run training programs? Well here’s a chance to get some cold, hard cash to help with operations. Every year, the NRA Foundation Grant Program provides hundreds of grants to deserving organizations. The 2017 Grant Application is now available. CLICK HERE to Apply for a Grant.
Since its inception, the NRA Foundation has funded over 41,000 grants totaling over $300 million. Grants went to qualified local, state and national shooting sports programs, hunting and conservation programs, Second Amendment education and for the preservation of historical firearms.
Grant money comes from generous donors and volunteer fund-raising efforts. Through its Grant Program the NRA Foundation seeks to: 1) Promote shooting sports and hunting safety; 2) Help educate individuals in proper firearms use and marksmanship; and 3) Enhance shooting range facilities and support active shooting sports organizations.
Range Improvement Grants
Helping clubs improve shooting range facilities is one of the main missions of the NRA Grant Program. Such programs might include: Berm improvements (example below), Clubhouse improvements, Covered firing lines, Road improvements, Trap Machines, and other permanent improvements to club properties and/or facilities.
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August 30th, 2016
 PMA Tool offers lightweight yet sturdy cleaning cradles that are quite affordable. PMA’s original cradle is ideal for benchrest rigs with a 3″-wide fore-end, and the price is just $69.95. There is also a version for 2.5-inch wide hunter-style fore-ends. PMA’s cleaning cradles measure 17″ in length, weighs about one pound, and secure your rifle in a muzzle-down position. This “nose-down” layout allows easy cleaning and prevents solvents from running back into the action. All contact surfaces are covered by thick silicone rubber which grips the rifle securely yet cushions the stock from scratches.
These cradles were originally crafted with a 3″-wide front saddle for Benchrest and F-Open style stocks, but the silicone rubber “padding” and the shape of the saddles themselves make this cradle usable for narrower, flat fore-ends such as those found on Hunter Class and modern varmint stocks. There is also a 2.5-inch version, but we think the original 3″-inch wide cradle is more versatile.
PMA Tool co-founder Pat Reagin tells us: “We’ve had a lot of interest in our cradle since it appeared in some ads and folks saw me using it at the Super Shoot. Over the past couple years we have improved the design and added the 2.5-inch wide model.”
Product Tip by EdLongrange. We welcome reader submissions.
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August 29th, 2016
At the request of our readers, we provide select “Deals of the Week”. Every Monday morning we offer our Bargain selections. Here are some of the best deals on firearms, hardware, reloading components, 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.
1. Natchez — Special 5 Reloading Press Kit, $199.99
This is an excellent entry-level reloading kit, which is on sale for $199.99 at Natchez Shooters Supplies. We like the relatively compact Special 5 press for most reloading duties. Eventually you may want to add an additional, large heavy press, but this will get the job done. This kit includes an RCBS Powder Measure, Digital Scale, Powder Trickler, Hand Priming Tool, Load Manual, Loading Tray, and more. It’s hard to beat this combination of tools for under $200.00.
2. Grafs.com — $99.99 Electronic Earbud Headset 31dB NRR
Walker’s new Razor-X and Razor-XV operate like electronic muffs — allowing you to hear commands and conversations while still blocking loud noises. The Razor-X combines a collar unit (containing the electronics) with retractable, foam-tipped ear buds. Unlike conventional earmuffs, the Razor-X system doesn’t interfere with your cheek weld. The patent-pending earbuds provide an impressive 31dB of noise reduction, with the ability to hear commands. To ensure a good fit (for best noise reduction), the Razor-X and Razor-VX come with two styles of noise-reducing foam tips. An AC wall adapter with USB port and a one-meter micro USB cord is provided. READ Razor-X User Reviews.
3. Amazon — AR500 Steel 8″-Diameter Gong, $19.95 Delivered
We like reactive targets. It’s fun to “ring steel” and see a target move instantly when hit. For just twenty bucks (including shipping), it’s hard to go wrong with this 8″ AR500 Steel Gong. The 8″-diameter size is big enough for zeroing at 200 yards, yet offers a nice challenge at 500 yards and beyond. There is also a 6″-diameter model for $16.00.
4. Cabelas — Big Ammo Sale Plus FREE Shipping
Right now, Cabela’s is running a big sale on all types of ammunition from major manufacturers. Save as much as 20% off regular pricing. For example, Winchester 9mm pistol ammo is marked down from $13.99 to $11.99 for 50 rounds. And PMC X-Tac 5.56×45 ammo is reduced from $9.99 to $8.49 for 20 rounds. Plus, you can get FREE SHIPPING on all orders of $99.00 or more. Use Code 86BUY during checkout (code valid through 8/31/2016).
5. Kelbly.com — 15% Off Discount on All Products
Looking for a Panda or Atlas Action, or a complete match rifle? Here’s a great promotion from our friends at Kelbly’s. Now through Tuesday, August 23, 2016 you can get 15% of ANYthing on the Kelblys.com website. That includes rifles, actions, stocks, barrels, scope rings, muzzle brakes, Berger bullets, accessories and more. To save big, use code 15ALL at checkout. Don’t delay — this offer expires at 11:59 pm on September 1, 2016.
6. Midsouth — Complete Case Tumbling Kit, $73.70
This brass tumbling system contains everything you need to clean your cartridge brass: Vibratory Case Tumbler, Rotary Media Separator, 6 lbs. of Corn Cob Media, and 8 oz. of Brass Polish. Right now this whole system is on sale at Midsouth for just $73.70. The case tumbler, which holds 450 .223 Rem cases or 1000 9mm cases, has a three-year motor warranty. This is a good deal for the package. You could pay $65.00 for a good vibratory Tumbler by itself.
7. Natchez Shooters Supply — 325 Rounds .22 LR Ammo, $22.99
This Federal .22 LR ammo is just 7 cents per round — the kind of pricing on bulk rimfire ammo we used to see in the “good old days”. Act quickly, this $22.99 Federal .22 LR Ammo deal won’t last long. Each box contains 325 rounds — enough ammo for many sessions at the range. The bullets are 40 grains, solid lead.
8. CDNN — Browning A-Bolt with Nikon Scope, $639.99 w/Rebate
Right now you can get a nice, wood-stocked Browning A-Bolt III Hunting rifle in .308 Winchester for just $689.99. And, to sweeten that deal, the current “Browning Benjamins” Rebate program knocks $50.00 off, so the price (with rebate) is just $639.99. This package includes a Nikon Buckmaster II 4-12x40mm BDC scope. This same Browning/Nikon special is available in many other chamberings for the same price: .243 Win, .270 Win, .270 WSM, 7mm-08, .30-06 Spr, .300 Win Mag.
9. Browning — Save Up to $100 on Browning Firearms (Rebates)
Now through the end of September, 2016, Browning is offering substantial cash rebates on rifles, pistols, and shotguns. Save $100.00 on a shotgun, $50.00 on a rifle, or $25.00 with this rebate offer, good on firearms purchases made by September 30th. Browning makes some pretty darn good firearms. This Editor owns a Browning Citori Shotgun and it’s a gem. CLICK HERE for details and Rebate Form.
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August 27th, 2016
McMillan Fiberglass Stocks is introducing a new F-Class Open Division stock. This offers a low profile fore-end and parallel geometry for improved tracking. This is similar to McMillan’s previous F-Open stock, but with important enhancements. Here is Kelly McMillan’s report:
“Our new Kestro is … made specifically for F-Class Open competition. Notice we have kept the low profile fore-end while increasing the mass and rigidity. The fore-end is not only ‘dead nuts’ in line with the butt stock, but it is also on an exactly parallel plane so when it recoils there is no rise or lateral shift in the cross hairs.
This model comes with an integral adjustable cheek-piece and can have our standard buttplate or our lightweight 3-way adjustable butt plate. My estimation is that this stock will weigh as light as 4.5 pounds fully dressed, or as much as 8 pounds depending on what you need.
We are currently working on the cheek-piece free model for those of you who don’t put your face on the stock. One more thing, this color combination we call a Tiger Stripe Maple.” Editor’s NOTE: Though “maple” is in the stock color name, this is a reinforced fiberglass stock, not wood.
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August 27th, 2016
The Remington 700 is the most popular bolt-action rifle in America, at least according to Gunbroker.com sales figures for new and “previously-owned” rifles. So, chances are that you (or a close family member) may have a Rem 700 of some vintage sitting in the gunsafe. But do you have a copy of the official Remington 700 product manual in digital PDF format? Probably not.
To get you squared away, CLICK HERE for a PDF version of the latest Remington 700 Owner’s Manual (also covers models Seven, and 673).
Here are links for other Remington Manuals (Right lick and “Save As” to Download):
Owner’s Manuals
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August 27th, 2016
Everybody knows that powerful spotting scopes work best when mounted to a stable tripod or otherwise secured to a steady mount. Yet when most folks use binoculars, they never even think of using a tripod, despite the fact that tripod adapters are available for many premium binoculars. A serious hunter should learn how to glass with tripod support. With binoculars offering more that 8X magnification, you can really benefit from a steady mount. In this article, Mark Boardman of Vortex Optics, an experienced hunter, explains the benefits of using a tripod with high-magnification binoculars.
READ FULL ARTICLE with More Tips for Hunters
Story tip by EdLongrange. We welcome reader submissions.
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August 26th, 2016
John Whidden of Whidden Gunworks used the .243 Winchester cartridge to win the 2016 NRA Long Range Championship, his fourth LR title at Camp Perry. John selected the .243 Win because it offers excellent ballistics with manageable recoil. John says that, at least for a sling shooter, the .243 Win is hard to beat at long range. Yes, John says, you can get somewhat better ballistics with a .284 Win or .300 WSM, but you’ll pay a heavy price in increased recoil.
.243 Winchester — The Forgotten 6mm Cartridge for Long Range
by John Whidden, 2016 National Long Range Champion
My experience with the .243 cartridge for use as a Long Range High Power cartridge dates back about 10 years or so. After building a .300 WSM, I realized that the recoil was hurting the quality of my shots. The WSM shot great, but I couldn’t always execute good shots when shooting it. From here I built a 6.5-284, and it shot well. I also had a very accurate 6mmBR at the time, and my logic in going to the .243 Win was to get wind performance equal to the 6.5-284 with recoil similar to the 6mmBR. The experiment has worked out well indeed!
Championship-Winning Load: Berger Bullets, Lapua Brass, and Vihtavuori N160
For a load, currently I’m shooting Lapua brass, PMC primers (Russian, similar to Wolf), VihtaVuori N160 single-base powder, and Berger 105 grain Hybrid bullets. I switched to the Hybrid bullets fairly recently at the beginning of the 2015 season. Previously I shot the 105gr Berger hunting VLDs, and in testing I found that the Hybrids were just as accurate without having to seat the bullet into the lands. The velocity of this combination when shot through the excellent Bartlein 5R barrels (32” length) is around 3275 FPS.
For my match ammo, I seat the Berger 105 Hybrids well off the lands — my bullets are “jumping” from .035″-.060″. I only use one seating depth for ammunition for multiple guns (I know some benchrest shooters will stop reading right here!) and the bullets jump further in the worn barrels than in the fresh barrels. The bullets are pointed up in our Bullet Pointing Die System and are moly-coated. The moly (molybdenum disulfide) does extend the cleaning interval a little bit, probably 20% or so. The Lapua .243 Win brass is all neck-turned to .0125″ thickness.
Whidden’s .243 Win Ammo is Loaded on a Dillon
My loading process is different than many people expect. I load my ammo on a Dillon 650 progressive press using our own Whidden Gunworks dies. However powder charges are individually weighed with a stand-alone automated scale/trickler system from AutoTrickler.com (see below). Employing a high-end force restoration scale, this micro-processor controlled system offers single-kernel precision. The weighed charges are then dropped into the cases with a funnel mounted to the Dillon head.
The Lapua .243 Win brass is full-length sized every time, and I run one of our custom-sized expanders in my sizer die. The expander measures .243″ which yields the desired .001″ neck tension. In my experience, the best way to get consistent neck tension is to run an expander in the case neck at some point. When sizing the case neck by a minimal amount such as is the case here, I don’t find any negative points in using an expander in the sizer die.
In my experience, the keys to accurate long range ammo are top quality bullets and the most consistent neck tension you can produce. From these starting points, the use of quality components and accurate powder measurement will finish out the magic.
Great Ballistics with 6mm 105s at 3275 FPS
Running at an impressive 3275 FPS, Berger 6mm 105 grain Hybrids deliver ballistics that are hard to beat, according to John Whidden:
“My .243 Win shoots inside a 6.5-284 with 142-grainers. Nothing out there is really ahead of [the .243], in 1000-yard ballistics unless you get into the short magnums or .284s and those carry a very significant recoil penalty. In the past I did shoot the 6.5-284. I went to the .243 Win because it had similar ballistics but had much less recoil. It doesn’t beat me up as much and is not as fatiguing.
With the .243 Win, there’s no tensing-up, no anticipating. With the reduced recoil (compared to a 7mm or big .308), I can break and shoot very good quality shots. I find I just shoot better shots with the .243 than I ever did with the 6.5-284.”
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August 26th, 2016
If you ever shoot factory ammo, you should consider getting Ammo & Ballistics 5. This resource book lists over 2,600 different loads for 190 cartridge types from 17 Mach 2 up to .700 Nitro Express, including the most popular centerfire and rimfire cartridges (both rifle and handgun). There are over 1,400 tables with ballistics data for nearly all commercially-loaded hunting ammunition sold in the United States (as of 2013, the publication date). Tables include velocity, energy, wind drift, bullet drop, and ballistic coefficient.
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This book can be helpful when choosing ammo for a hunt. You can quickly compare the velocity and knock-down power of various types of commercial ammo. In addition, this book can help you choose a caliber/chambering for your next hunting rig, as you can compare factory load options.
Book Purchaser Reviews
“The data contained in this book is invaluable. If you don’t understand momentum vs. energy, MER and MEPBR, this book will help you gain an understanding. If you don’t know what the Taylor Knock Out (KO) Index is, this book will enlighten and inform.” — Daryl ID
“Great heaps of data! This volume has pages and pages of new data for .22LR like the hot Velocitor, and also on the .22 WMR from 30 grains up into the 50s. Most importantly there is lots of range data, drop, windage, kinetic energy, etc. — Terrific reference guide….” — E. Svanoe |
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August 25th, 2016
With suicide accounting for nearly two-thirds of all firearm fatalities annually, the topic of suicide prevention deserves our attention. In recent years NSSF has worked with the Veterans Administration, the State of Utah, and mental health agencies to help educate gun owners and the public on how to keep firearms safely out of reach of those who, during a period of despair, decide to do themselves harm.
According to Centers for Disease Control and Prevention (CDC) Data:
1. Nearly half of all suicides were by firearm in 2014.
2. Suicide accounted for almost two-thirds of gun deaths in 2014.
3. 90 percent of suicide attempts with a firearm are fatal.
The NSSF has committed to broaden its efforts, in partnership with the American Foundation for Suicide Prevention (AFSP). Recently, NSSF and AFSP announced a partnership to embark on a first-of-its-kind national plan to build and implement public education resources for firearms retailers, shooting ranges, and the firearms-owning community about suicide prevention and firearms.
Experts say that suicide results from the culmination of several health and life factors, with the decision to act often being made in minutes. Keeping firearms securely stored puts space between the period of risk and the means to act, and sometimes that … can help save a life.
AFSP has commenced a four-state pilot program that will involve firearms retailers and shooting ranges. This pilot program employs AFSP/NSSF jointly-developed strategies and resources to inform firearm owners about warning signs, prevention resources and secure firearms storage options. The NSSF also supports AFSP’s Project 2025, an initiative to reduce the annual suicide rate 20 percent by 2025. You will be hearing more about AFSP and NSSF efforts in this area.
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August 25th, 2016
Summer is almost over. That’s means hunting season is coming soon. To help you prepare for your fall hunts, NRABlog.com has created a set of color practice hunting targets. You can hone your skills on a trio of bucks, three gobblers, or three wild hogs.
Each target features three red bullseyes, centered on the animals. You can print the targets in black and white, but they look best in color. Click on each image below to download a FREE printable PDF file.
As the NRA Blog says: “Print out the turkey target, grab your shotgun, and head to the outdoor range. Or, try your hand at deer and hog while zeroing your rifle.”
RIght-Click Each Image to Download Printable PDF File:
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August 24th, 2016
In this .308 Win test, 70° F ammo shot 96 FPS slower than ammo heated to 130.5° F. And the 130.5° ammo was 145 fps faster than ammo right out of the freezer (at 25.5° F). That’s a huge difference…
EDITOR’s NOTE: The Sierra tester does not reveal the brand of powder tested here. Some powders are much more temp sensitive than others. Accordingly, you cannot extrapolate test results from one propellant to another. Nonetheless, it is interesting to see the actual recorded velocity shift with ammo temperature variations in a .308 Win.
Written by Sierra Chief Ballistician Tommy Todd
This story originally appeared in the Sierra Bullets Blog
A few weeks ago I was attending the Missouri State F-Class Match. This was a two-day event during the summer and temperatures were hot one day and hotter the next. I shot next to a gentleman who was relatively new to the sport. He was shooting a basically factory rifle and was enjoying himself with the exception that his scores were not as good as he hoped they would be and he was experiencing pressure issues with his ammunition. I noticed that he was having to force the bolt open on a couple of rounds. During a break, I visited with him and offered a couple of suggestions which helped his situation somewhat and he was able to finish the match without major issues.
He was shooting factory ammunition, which is normally loaded to upper levels of allowable pressures. While this ammunition showed no problems during “normal” testing, it was definitely showing issues during a 20-round string of fire in the temperatures we were competing in. My first suggestion was that he keep his ammunition out of the direct sun and shade it as much as possible. My second suggestion was to not close the bolt on a cartridge until he was ready to fire. He had his ammo in the direct sunlight and was chambering a round while waiting on the target to be pulled and scored which can take from a few seconds to almost a minute sometimes.
This time frame allowed the bullet and powder to absorb chamber [heat] and build pressure/velocity above normal conditions. Making my recommended changes lowered the pressures enough for the rifle and cartridge to function normally.
Testing Effects of Ammunition Temperature on Velocity and POI
After thinking about this situation, I decided to perform a test in the Sierra Bullets underground range to see what temperature changes will do to a rifle/cartridge combination. I acquired thirty consecutive .30 caliber 175 grain MatchKing bullets #2275 right off one of our bullet assembly presses and loaded them into .308 Winchester ammunition. I utilized an unnamed powder manufacturer’s product that is appropriate for the .308 Winchester cartridge. This load is not at the maximum for this cartridge, but it gives consistent velocities and accuracy for testing.
I took ten of the cartridges and placed them in a freezer to condition.
I set ten of them on my loading bench, and since it was cool and cloudy the day I performed this test I utilized a floodlight and stand to simulate ammunition being heated in the sun.
I kept track of the temperatures of the three ammunition samples with a non-contact laser thermometer.
The rifle was fired at room temperature (70 degrees) with all three sets of ammunition. I fired this test at 200 yards out of a return-to-battery machine rest. The aiming point was a leveled line drawn on a sheet of paper. I fired one group with the scope aimed at the line and then moved the aiming point across the paper from left to right for the subsequent groups.
NOTE that the velocity increased as the temperature of the ammunition did.
The ammunition from the freezer shot at 2451 fps.
The room temperature ammunition shot at 2500 fps.
The heated ammunition shot at 2596 fps.
The tune window of the particular rifle is fairly wide as is shown by the accuracy of the three pressure/velocity levels and good accuracy was achieved across the board. However, notice the point of impact shift with the third group? There is enough shift at 200 yards to cause a miss if you were shooting a target or animal at longer ranges. While the pressure and velocities changed this load was far enough from maximum that perceived over pressure issues such as flattened primer, ejector marks on the case head, or sticky extraction did not appear. If you load to maximum and then subject your ammunition to this test your results will probably be magnified in comparison.
This test showed that pressures, velocities, and point-of-impact can be affected by temperatures of your ammunition at the time of firing. It’s really not a bad idea to test in the conditions that you plan on utilizing the ammo/firearm in if at all possible. It wouldn’t be a bad idea to also test to see what condition changes do to your particular gun and ammunition combination so that you can make allowances as needed. Any personal testing along these lines should be done with caution as some powder and cartridge combination could become unsafe with relatively small changes in conditions.
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