For today’s Sunday GunDay story, we feature highlights from two in-depth reports on rifles built around the relatively new 6GT cartridge (also known as the “6mm GT”). Developed by George Gardner (G.A. Precision) and Tom Jacobs (Vapor Trail), the 6GT was designed to feed well from magazines, be more efficient than the 6mm Creedmoor, and offer outstanding accuracy. It is just enough bigger than the 6mmBR or 6 Dasher so it feeds better. But it retains many of the qualities of the 6mmBR (high efficiency and outstanding accuracy). Burning significantly less powder than the 6mm Creedmoor, the 6GT is a bit less expensive to shoot, and should, theoretically at least, deliver better barrel life.
“The [6GT] is a more predictable and barrel-friendly cartridge than the 6mm Creedmoor. It can utilize the accurate and forgiving powders of the 6BR, has fantastic accuracy, and due to its shoulder angle and case length, it doesn’t suffer from feeding issues.” — PewPewTactical.com
We should say that the 6 Dasher has been used very successfully in PRS/NRL competition, with some aftermarket magazine accessories. For this reason, if you already shoot a 6 Dasher, moving to a 6GT may not be worth the cost of new dies and new brass. A.J. Deysel, writing for LoadDevelopment.com, writes:
“The longer case of the 6mm GT means it feeds as reliably from a magazine as a 6mm Creedmoor, and offers slightly higher powder capacity and in turn velocities than the 6mmBR variants, whilst still being able to use the same accurate and forgiving propellants.
You will also find many competitive and average Joes shooting 6mmBR and 6mm Dashers with a Primal Rights or some other mag conversion kit, having very few if any mag-feed issues at all, so that pretty much also nullifies the need to move away from those [chamberings] if you already own one of those or the reloading equipment for it.” — LoadDevelopment.com
Part I: The 6GT Cartridge for Precision Rifle Competition
Report by Vu Pham
I was ready to build a 6 Dasher when I saw a lot of buzz… about a new caliber George Gardner (Owner of G.A. Precision) and Tom Jacobs (Owner of Vapor Trail Bullets) designed, the 6GT. After some research and talking to George, I ditched the 6mm Dasher build and had GA Precision build me a 6GT on a GAP Templar action I already had in the safe. The reasons to try the 6GT in a new PRS-style rig were as follows:
1. Push a 110-115 grain class bullet at 2880-2930 FPS safely in the Sacramento heat.
2. Achieve a load that is reliable and predictable. The caliber must be easy-to-tune and predictable from barrel to barrel. I don’t want to spend weeks developing a new load each time I spin on a fresh barrel.
3. Be able to run the same mag in all my guns without having to tweak or use mag kits. The round must feed from AICS and AW magazines without major tweaking or hiccups.
4. Get good barrel life. The barrel needs to go 2200-2500 rounds with match-grade reliability and accuracy.
5. Have a competitive cartridge with the least possible recoil without sacrificing too much performance down range, compared to bigger options like the 6mm Creedmoor.
6GT feeding from un-modified magazines has been flawless in all the rifles we tested. The 6GT feeds so well, I sometimes have to do a press check to ensure there is a round in the chamber.
On paper the 6GT seemed like the perfect cartridge for PRS- and NRL-style competition. It has the low recoil of a 6 Dasher, with good feeding and mag compatibility. With the 6GT, a competitor can push 105gr bullets at 3000+ FPS or run heavier bullets at 2800-2900+ FPS.
Knowing that I would initially have to make my own 6GT brass and do quite a bit of load development, I enlisted the help of Dan Bertocchini with CS Tactical. Dan has a lot more experience with wildcats and is the man when it comes to this type of data gathering. He has been running a 6 Dasher for a few years so I was curious how he would compare the 6GT to his 6 Dasher.
Quick Summary: “I am really digging the 6GT and the capabilities it offers. It can launch 103gr Vapor Trails at 3000+ FPS or lob heavy 115gr DTACs in the low-to-mid 2900s comfortably. I think we will see this cartridge go mainstream in PRS/NRL-style competition in 2020.” — Vu Pham
The new 6GT Cartridge Was Tested in Three (3) Tactical Rifles:
Rifle 1: Vu’s 6GT 1.0
Builder: GA Precision
Action: Left Hand GAP Templar (large firing pin)
Barrel: Bartlein 7.7 Twist finished at 26″ with a 419 Hellfire Brake
Stock: KMW Sentinel
Optic: Vortex Razor Gen II 4.5-27x56mm EBR-7C MRAD
Bi-Pod: Harris
Trigger: Timney Calvin Elite
Magazines: AICS and AW
Support Bag: Wiebad Fortune Cookie
Rifle 2: Vu’s 6GT 2.0
Builder: Rubicon Precision
Action: Impact Precision 737
Barrel: Bartlein 7.0 Twist finished at 27″ with a 419 Hellfire Brake
Stock: XLR Industries Envy Chassis
Optic: Vortex Razor Gen II 4.5-27x56mm EBR-7C MRAD
Bi-Pod: Harris with Henderson Arca adapter
Trigger: Trigger Tech Diamond
Magazines: AICS and AW
Support Bag: Wiebad Fortune Cookie
Rifle 3: Dan’s 6GT
Builder: CS Tactical
Chambered by: Rubicon Precision
Action: Lone Peak Arms Fusion
Barrel: Proof 7.0 Twist finished at 28″ with a Muzzle Brake and More Brake
Stock: XLR Industries Envy Chassis
Optic: Minox ZP5 5-25x56mm MR4
Bi-Pod: Arca Cyke Pod (PRS)
Trigger: Trigger Tech Diamond
Magazines: MDT
Support Bag: Armageddon Gear OG Game Changer, Waxed Canvas
Alpha Munitions Pre-Production 6GT Brass George Gardner was kind enough to send us 50 pieces of Pre-Production Alpha 6GT brass for preliminary testing. Like the cases I formed from 6.5×47 Lapua brass, the Alpha 6GT brass will use a small rifle primer. Purchased direct from Alpha Munitions, 6GT brass is now $1.30 per case, which is comparable with Lapua 6mm Creedmoor brass, currently $120.99/100 at Grafs.com.
The major difference between 6.5×47 Lapua-formed brass and Alpha 6GT brass is the case capacity. Alpha 6GT brass has 1.5 to 1.7 grains more case capacity. When a piece of 6.5×47 Lapua brass is formed into a 6GT, the walls of the case now become the shoulder and part of the neck. In a normal piece of brass, the shoulder and neck are typically thinner because of the thickness of the brass tapering from the body to neck.
While the cartridge design was optimized for Hodgdon Varget, the extra case capacity of the Alpha 6GT brass opens the door to Hodgdon H4350 (my favorite powder) and Alliant Reloder 16.
Test Results with Alpha Munitions 6GT Brass
Initial test results were as expected from a premium brass-maker. Dan and I both got excellent Standard Deviations and Extreme Spreads over my MagnetoSpeed V3 and his LabRadar. This string below was with 112gr Barnes Match Burners and 33.8 grains of Varget. Can’t complain about a 3 FPS Extreme Spread!
Yes, H4350 Works with the Alpha Munitions Brass
Personally, I prefer running Alpha 6GT brass with H4350 rather than Varget pushing a heavier bullet. H4350 burns slower and cleaner which should equate to better barrel life. The Lapua-formed 6GT cases just do not have the capacity to reach the cartridge’s full capability with the slower burning powders.
Is the 6GT cartridge accurate? Definitely. Here is a 5-shot group at 600 yards shot by Dan. This was Alpha 6GT brass, with Hodgdon H4350 pushing Barnes 112gr Match Burner bullets.
PART II — 6GT Load Development with Multiple Powders
This text is taken from a full report by Mike McCasland on his 6GT (aka “6mm GT”) bolt action rifle. This rig was designed for general use, not just for PRS/NRL matches. In his 6GT rifle, Mike tested multiple powders including Varget, H4350, Reloder 16, Reloder 15, Shooters World Precision, and Vihtavuori N140. For more details, CLICK HERE for full report.
About the 6mm GT Cartridge
BRASS — The first thing you’ll find is cartridge brass choices for the 6 GT are rather limited currently. At present, the only commercial options are Hornady and Alpha Munitions. For the die-hard Lapua fans, you can technically make 6mm GT brass from 6.5×47 Lapua, however that process is very labor-intensive.
I have used both Hornady and Alpha brass in this rifle and haven’t noticed much difference between the two. I will say that my batch of Alpha brass was slightly softer than Alpha brass I’ve used in other calibers; you could feel a difference when neck turning cases. I’m unsure if that’s a batch issue, or something specific to their 6mm GT brass as a whole. As far as performance, there was little discernable difference. Oddly enough, the Hornady brass seemed to have slightly less case capacity than the Alpha; with most other cartridges it’s the other way around.
POWDERS — The 6mm GT was designed with Hodgdon Varget in mind, and that popular powder works exceedingly well in this platform. That said, the 6mm GT can work with a wide variety of powders, some yielding better performance than Varget.
I’ve tried a multitude of powders during my initial 6mm GT load development: Varget, Shooters World Precision, RL16, VV N140, H4350, and RL-15 to name a few. In my barrel, Hodgdon H4350 seems to deliver the best velocity/accuracy combination. SD and ES also seemed to be the lowest with H4350.
Load Development for the 6mm GT — Many Powders Tested
BULLETS — The most common 0.120″ freebore chamber allows for the majority of high-BC 6mm projectiles found in both F-Class and PRS. I had good luck with the pointed 107gr Sierra Match Kings (SMK), as well as the 110gr Hornady A-Tips in my rifle. For those looking to run the heavier 112-115 grain 6mm offerings, I believe GAP designed a 0.160″ freebore reamer that gets those bullets out of the neck/shoulder junction. Shown below is the 0.120″ freebore JGS reamer print:
SUMMARY — Good Cartridge with Much Potential
Generally speaking, I think the 6mm GT is a good little round. Some may not subscribe to this theory, but I believe some cartridges are inherently easier to tune than others. I’m not sure the 6mm GT is as easy-to-tune as a 6mmBR, 6 Dasher, or 6 BRA, but I don’t think it lags that far behind.
With relatively little trouble, I was able to find loads with both Varget and H4350 that would consistently shoot very well — 0.2 to 0.3 MOA. Moreover, I found the 6GT cartridge lives up to the velocity claims made by G.A. Precision. I was easily able to push the 110gr A-Tips to 2950 FPS, and the 107gr SMKs to low 3000 FPS range without any pressure signs, or unnecessary wear and tear on the brass.
As a fun test, I ran my 6mm GT rifle in a local 1000-yard F-Class match with the 110gr A-Tips, just to see just how well they would perform. Although wind conditions of the day and some E-Target issues prevented my 6mm GT rig from getting the better of the larger 7mm and .30-Cal rifles, the 6mm GT proved itself an accurate little round at distance. Here is a 1000-yard ShotMarker target:
After putting several hundred rounds through my 6mm GT rifle, I anticipate building another 6GT on a repeater action to give PRS a try. I think if you are looking for a dual-purpose rifle that can run tactical matches (with 100% feeding reliability), and can also be used for mid-range, F-Open Class competition, the 6mm GT would be a very good option.
About the author, Mike McCasland:
Mike McCasland is an avid shooter who competes regularly in F-Class matches. Based in Texas, Mike is the creator of the Texas Precision YouTube Channel. There you’ll find many videos covering reloading, gun projects, and marksmanship. Mike has done some notable product reviews including a comparison test of Micrometer Competition Seating Dies. To access Mike’s YouTube Channel, CLICK HERE.
Here’a useful article by Sierra Bullets Media Relations Manager Carroll Pilant. This story, which originally appeared in the Sierra Bullets Blog, covers some of the more common ammo problems that afflict hand-loaders. Some of those issues are: excessive OAL, high primers, and improperly-sized cases. Here Mr. Pilant explains how to avoid these common problems that lead to “headaches at the range.
I had some gentlemen at my house last fall getting rifle zeros for an upcoming elk hunt. One was using one of the .300 short mags and every 3rd or 4th round would not chamber. Examination of the case showed a bulge right at the body/shoulder junction. These were new cases he had loaded for this trip. The seating die had been screwed down until it just touched the shoulder and then backed up just slightly. Some of the cases were apparently slightly longer from the base to the datum line and the shoulder was hitting inside the seating die and putting the bulge on the shoulder. I got to thinking about all the gun malfunctions that I see each week at matches and the biggest percentage stem from improper handloading techniques.
One: Check Your Cases with a Chamber Gage
Since I shoot a lot of 3-gun matches, I see a lot of AR problems which result in the shooter banging the butt stock on the ground or nearest solid object while pulling on the charging handle at the same time. I like my rifles too well to treat them that way (I cringe every time I see someone doing that). When I ask them if they ran the ammo through a chamber gage, I usually get the answer, “No, but I need to get one” or “I didn’t have time to do it” or other excuses. The few minutes it takes to check your ammo can mean the difference between a nightmare and a smooth running firearm.
A Chamber Gauge Quickly Reveals Long or Short Cases
Size Your Cases Properly
Another problem is caused sizing the case itself. If you will lube the inside of the neck, the expander ball will come out a lot easier. If you hear a squeak as the expander ball comes out of a case neck, that expander ball is trying to pull the case neck/shoulder up (sometimes several thousandths). That is enough that if you don’t put a bulge on the shoulder when seating the bullet … it can still jam into the chamber like a big cork. If the rifle is set up correctly, the gun will not go into battery and won’t fire but the round is jammed into the chamber where it won’t extract and they are back to banging it on the ground again (with a loaded round stuck in the chamber). A chamber gage would have caught this also.
Oversizing cases also causes problems because the firing pin doesn’t have the length to reach the primer solid enough to ignite it 100% of the time. When you have one that is oversized, you usually have a bunch, since you usually do several cases at a time on that die setting. If the die isn’t readjusted, the problem will continue on the next batch of cases also. They will either not fire at all or you will have a lot of misfires. In a bolt action, a lot of time the extractor will hold the case against the face of the breech enough that it will fire. The case gets driven forward and the thinner part of the brass expands, holding to the chamber wall and the thicker part of the case doesn’t expand as much and stretches back to the bolt face. If it doesn’t separate that time, it will the next time. When it does separate, it leaves the front portion of the case in the chamber and pulls the case head off. Then when it tries to chamber the next round, you have a nasty jam. Quite often range brass is the culprit of this because you never know how many times it has been fired/sized and in what firearm. Back to beating it on the ground again till you figure out that you have to get the forward part of the case out.
Just a quick tip — To extract the partial case, an oversized brush on a cleaning rod [inserted] and then pulled backward will often remove the case. The bristles when pushed forward and then pulled back act like barbs inside the case. If you have a bunch of oversized case that have been fired, I would dispose of them to keep from having future problems. There are a few tricks you can use to salvage them if they haven’t been fired though. Once again, a case gage would have helped.
Two: Double Check Your Primers
Another thing I see fairly often is a high primer, backwards primer, or no primer at all. The high primers are bad because you can have either a slam fire or a misfire from the firing pin seating the primer but using up its energy doing so. So, as a precaution to make sure my rifle ammo will work 100% of the time, I check it in a case gage, then put it in an ammo box with the primer up and when the box is full, I run my finger across all the primers to make sure they are all seated to the correct depth and you can visually check to make sure none are in backwards or missing.
Three: Check Your Overall Cartridge Length
Trying to load the ammo as long as possible can cause problems also. Be sure to leave yourself enough clearance between the tip of the bullet and the front of the magazine where the rounds will feed up 100%. Several times over the years, I have heard of hunters getting their rifle ready for a hunt. When they would go to the range to sight in, they loaded each round single shot without putting any ammo in the magazine. On getting to elk or deer camp, they find out the ammo is to long to fit in the magazine. At least they have a single shot, it could be worse. I have had hunters that their buddies loaded the ammo for them and then met them in hunting camp only to find out the ammo wouldn’t chamber from either the bullet seated to long or the case sized improperly, then they just have a club.
Four: Confirm All Cases Contain Powder
No powder in the case doesn’t seem to happen as much in rifle cartridges as in handgun cartridges. This is probably due to more handgun ammo being loaded on progressive presses and usually in larger quantities. There are probably more rifle cartridges that don’t have powder in them than you realize though. Since the pistol case is so much smaller internal capacity, when you try to fire it without powder, it usually dislodges the bullet just enough to stick in the barrel. On a rifle, you have more internal capacity and usually a better grip on the bullet, since it is smaller diameter and longer bearing surface. Like on a .223, often a case without powder won’t dislodge the bullet out of the case and just gets ejected from the rifle, thinking it was a bad primer or some little quirk.
For rifle cases loaded on a single stage press, I put them in a reloading block and always dump my powder in a certain order. Then I do a visual inspection and any case that the powder doesn’t look the same level as the rest, I pull it and the one I charged before and the one I charged after it. I inspect the one case to see if there is anything visual inside. Then I recharge all 3 cases. That way if a case had powder hang up and dump in the next case, you have corrected the problem.
On progressive presses, I try to use a powder that fills the case up to about the base of the bullet. That way you can usually see the powder as the shell rotates and if you might have dumped a partial or double charge, you will notice as you start to seat the bullet if not before. On a progressive, if I don’t load a cartridge in one smooth stroke (say a bullet tipped over sideways and I raised the ram slightly to reset it) Some presses actually back the charge back adding more powder if it has already dumped some so you have a full charge plus a partial charge. When I don’t complete the procedure with one stroke, I pull the case that just had powder dumped into it and check the powder charge or just dump the powder back into the measure and run the case through later.
The CMP National Rimfire Sporter Match is a fun competition with affordable smallbore rifles with either scopes or iron sights. All you need are a .22 LR rifle, sling, and ammo.
Each year, the Rimfire Sporter Match attracts hundreds of shooters to Camp Perry on the shores of Lake Erie. If there is a single CMP event at Camp Perry that offers the most diverse group of competitors (of all ages), and the lowest cost of entry, that would be the annual Rimfire Sporter Match.
This year’s summer match was held on Saturday, July 8, 2023 at the Viale Range during the first weekend of the National Match Schedule at Camp Perry. One of the most popular annual Camp Perry events, the Rimfire Sporter Rifle match features .22 LR competition in open sights (O-Class), telescopic (T-Class) and tactical/unlimited (TU) classes, fired at 25 and 50 yards. A CMP/AMU Rimfire Sporter Small Arms Firing School was held on July 7, 2023.
The Rimfire Sporter Match is for smallbore rifles that weigh 7 1/2 pounds or less with sights. Firing is done at 25 and 50 yards in prone, sitting and standing positions, in slow and rapid fire modes. The CMP has a special smart-phone App that will help speed up scoring.
Each year, the Rimfire Sporter Match attracts hundreds of shooters to the shore of Lake Erie at Camp Perry. The CMP National Rimfire Sporter Rifle Match offers shooters a recreation-oriented competition where they use affordable, smallbore sporter rifles with either scopes or iron sights. All you need are a .22 LR rifle, sling, and ammo.
Hundreds of shooters compete in the Rimfire Sporter Match at Camp Perry.
Prior to the match at Camp Perry, Rimfire Sporter competitors check-in, have their rifles weighed, triggers checked, and receive their squad assignments.
Rifles may be manually operated or semi-automatic, in three classes: the standard “O Class” for open-sighted rifles, “T-Class” for telescope-sighted rifles, and the “Tactical Rimfire” Class. Firing is done at 50 and 25 yards on a target with a 1.78″ ten-ring. The target is simple enough for a beginner to hit, yet challenging enough that only one competitor in the history of the match has ever fired a perfect 600 score.
Rimfire Sporter Course of Fire
At the Rimfire Sporter Match, competitors complete slow fire prone, rapid fire prone, slow fire sitting or kneeling, rapid fire sitting or kneeling, slow fire standing, and rapid fire standing shot sequences.
What is Required for the Camp Perry Rimfire Sporter Match
Competitors need to bring their own .22 cal. Rimfire rifle(s) and ammunition. Special target shooting equipment, shooting jackets, or shooting gloves are not permitted, but you can bring a spotting scope and ground cloth or shooting mat. The firing points have grass (sometimes a bit wet with rain). Competitors are strongly urged to wear hearing and eye protection. Assistance for disabled competitors is provided.
A free Shooters’ Clinic is usually held in connection with the Rimfire Sport match at Camp Perry. The Clinic covers Rimfire Sporter rules, safety instructions, course of fire, and competition procedures. Shooters who have not previously attended a CMP Rimfire Sporter Match are strongly encouraged to attend.
Do you want to see more Rimfire Sporter photos? CLICK HERE to view the CMP Zenfolio Archive with 1200+ photos from Rimfire Sporter Matches at Camp Perry and elsewhere.
Sierra Bullets has published load data for the 6mm Creedmoor cartridge, a necked-down version of the popular 6.5 Creedmoor. Sierra has released very comprehensive 6mm Creedmoor load data, covering fifteen (15) different bullets from 55 to 110 grains. NOTE: Hornady-brand brass was used for Sierra’s 6mm Creedmoor load tests, not the newer, stronger Lapua 6.5 CM brass with small primer pockets. Hand-loaders using Lapua 6.5 Creedmoor brass necked to 6mm may have to adjust their loads.
Sierra writes: “As soon as the 6.5 Creedmoor was released in 2007, a 6mm version was being envisioned. After the 6mm Creedmoor demonstrated its worth at 1000 yards it began to catch the attention of Precision Rifle Series (PRS) competitors. The 6mm Creedmoor is a great fit for those looking for an AR platform-friendly cartridge. It delivers velocities very similar to the .243 Win and yet fits the AR10 magazine length[.] The 30-degree shoulder makes this a very efficient case and helps prolong case life as well. The 6mm Creedmoor works well with powders such as H4350, [RE-16], RE-17, and Ramshot Hunter for heavier long-range bullet weights. Slightly faster powders such as RE-15, Win 760, and Vihtavuori N540 work well with lighter weight bullets.”
Sierra Bullets Tested for 6mm Creedmoor Load Data
55gr BlitzKing (#1502)
60gr HP (#1500)
70gr HPBT (#1505)
70gr BlitzKing (#1507)
75gr HP (#1510)
In developing its 6mm Creedmoor load data, Sierra tested a very wide selection of propellants, two dozen overall. For the smaller bullets, fast-burning powders such as Benchmark, H4895, and CFE223 were tested. For the heavier 100+ grain bullets, Sierra tested a selection of medium-burn-rate powders including H4350, Reloder 16, Reloder 17, Varget, and Superformance. Sierra did a very thorough job. We know this information will be welcomed by 6mm Creedmoor shooters.
Don’t know what powder to try first? For the 107-110 grain bullets, if you want best accuracy and low ES/SD, our Forum members recommend Alliant Reloder 16 and Hodgdon H4350. If you are seeking max velocity with the 110-grainer, look at Hodgdon Superformance and Reloder 19.
Here are Sierra’s 6mm Creedmoor Load Data Charts for 90-95 grain bullets plus the 107gr MK and 110gr MK. There are five other tables for other bullet types.
BONUS: PRB 6mm Creedmoor and 6.5 Creedmoor Load Survey
The Precision Rifle Blog compiled Load Data from PRS Competitors, for both 6mm Creedmoor and 6.5 Creedmoor. This is a good place to start. PRB surveyed the match loads for “173 of the top-ranked precision rifle shooters in the country”. One cautionary note: These PRS guys may be loading fairly hot, so work up gradually, 0.3 grains at a time. CLICK HERE.
From the late ’70s through 1983, a huge, concrete-walled warehouse in Houston was used for benchrest testing. Virgil King and Bob Fisher set up a bullet-catching backstop at the end of a 30-yard-wide, 325-yard-long fire lane that remained unobstructed even when the warehouse was in use. This allowed accuracy tests in virtually perfect “no wind” conditions. Over a six-year period, about 30 shooters were invited to test their rifles. The results were amazing, with numerous “zero groups” being shot in the facility. Many of the lessons learned in the legendary Houston Warehouse still help benchresters achieve better accuracy today.
Dave Scott explains why the Warehouse was so unique:
“Over a period of six years, the levels of accuracy achieved in the Houston Warehouse went beyond what many precision shooters thought possible for lightweight rifles shot from sandbags and aimed shot-to-shot by human eye. For the first time, a handful of gifted, serious experimenters — armed with the very best performing rifles (with notable exceptions) — could boldly venture into the final frontiers of rifle accuracy, a journey made possible by eliminating the baffling uncertainties of conditions arising from wind and mirage. Under these steel skies, a shooter could, without question, confirm the absolute limits of accuracy of his rifle, or isolate the source of a problem. In the flawlessly stable containment of the Houston Warehouse … a very few exceptional rifles would display the real stuff, drilling repeated groups measuring well below the unbelievably tiny .100″ barrier. The bulk of rifles, however, embarrassed their owners.”
Scott’s article also reveals some interesting technical points: “One thing that IS important is that the bullet be precisely seated against the lands. T.J. Jackson reported this fact in the May 1987 issue of Precision Shooting. In a letter to the Editor, T.J. wrote, ‘…in all our testing in that Houston warehouse… and the dozens and dozens of groups that Virgil King shot in there ‘in the zeroes’… he NEVER fired a single official screamer group when he was ‘jumping’ bullets. All his best groups were always seated into the lands, or at the very least… touching the lands. Virgil said his practice was to seat the bullets so the engraving was half as long as the width of the lands. He noticed an interesting phenomenon with rifles that could really shoot: if the bullets were seated a little short and the powder charge was a bit on the light side, the groups formed vertically. As he seated the bullets farther out and increased the powder charge, the groups finally became horizontal. If he went still farther, the groups formed big globs. He said the trick is to find the midway point between vertical and horizontal. That point should be a small hole.”
You should definitely read the complete article, as it provides many more fascinating insights, including shooting technique, barrel cleaning, neck-turning, and case prep.
EDITOR: Will the lessons of the Houston Warehouse work elsewhere? Is this repeatable magic? We remind readers that what T.J. Jackson discovered worked for his barrels, his cartridge type, and his choice of bullets. Jumping bullets can definitely produce good results in other cartridge types with bullets such as Berger Hybrids. Still, the Houston results are intriguing. Any time someone shoots in the “zeros” one should pay attention to how that was achieved.
The 38th annual Gun Rights Policy Conference (GRPC), co-hosted by the Second Amendment Foundation (SAF) and Citizens Committee for the Right to Keep and Bear Arms, will be held September 22-24, 2023, in Phoenix, Arizona. The conference is FREE to attend, if you pre-register in advance. CLICK HERE to register online.
The theme of this year’s event, which will be held at the Marriott Phoenix Airport Hotel, is “Road to Liberty!”. GRPC Registration is available online at the SAF website. If you are near Phoenix that weekend, you may definitely want to attend. For those unable to attend, the conference will be featured on multiple platforms including YouTube and Facebook.
As in the past, this year’s conference and all materials are FREE!
This year’s conference will be attended by more than 600 gun rights advocates and activists and will feature a veritable “Who’s Who” of leaders in the Second Amendment movement. More than 80 speakers will offer presentations on a variety of subjects, including legislation, the upcoming campaigns for the 2024 elections, firearms litigation, and more.
Notable scheduled speakers this year include Alan Gottlieb, Adam Kraut, Stephen Hallbrook, John Lott, Massad Ayoob, Mark Smith, AWR Hawkins, John Correia, Ryan and Tom Gresham, Mark Walters, Stephen Gutowski and representatives and staff from SAF, CCRKBA, FPC and GOA as well as leaders of state organizations. Learn more about the speakers on the GRPC Speaker Bio Page.
Gun Rights Policy Conference Schedule
Friday, September 22: The conference begins with registration and an evening reception, 7-9 pm.
Saturday, September 23: The conference gets fully underway with panel discussions, individual presentations, and the annual awards luncheon. It’s an all-day event running from 8 am to 6 pm.
Sunday, September 24: The conference has more panel discussions and reports from 9 am to 1 pm.
SAF founder and Executive V.P. Alan Gottlieb said this year’s GRPC event occurs at a critical time for the Second Amendment movement:
“Our rights have been under continuing and unrelenting attacks from the Biden administration. While we have seen several Second Amendment victories in the courts and the various state legislatures. We are witnessing continued growth in the number of legally-armed citizens, with more than half of the states now enjoying Constitutional/permitless carry.
“We’ve come a long way since the first GRPC was held in Seattle in 1986,” Gottlieb added. “We will be delighted to see old friends and make new ones, and we expect this year’s conference to be an awesome event for everyone.”
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.”
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.
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.
Most bolt-action rifle shooters work the bolt with their trigger-pulling hand. This is because most rifles sold to right-handed shooters come with right-side bolts, while “lefty” rifles come with left-side bolts. This “standard” configuration requires the shooter to take his dominant, trigger-pulling hand off the stock to cycle the bolt, then re-position his hand on the stock, and “re-claim” the trigger. Often the shooter must lift or move his head to work the bolt, and that also requires him to re-establish his cheek weld after each and every shot. Not good.
This really doesn’t make much sense for precision shooting with fore-end support*. There is a better way. If you leave your trigger hand in position and work the bolt (and feed rounds) with the opposite hand, then you don’t need to shift grip and head position with each shot. All this requires is a weakside-placed bolt, i.e. a left bolt for a right-handed shooter or a right bolt for a left-handed shooter. The video below shows a “Lefty” working a right bolt. Note how efficient this is:
As our friend Boyd Allen explains: “If you think about it, if you are going to work with a factory action where your options are left bolt and left port or right bolt and right port, and you are building a rifle that will only be shot from a rest, using the left/left for a RH shooter or using a right/right for a LH shooter works better than the conventional configuration”.
Shoot Like a Champ and Work the Bolt with Your Weakside Hand
Derek Rodgers is a recent F-TR World Champion, a King of 2 Miles champion, AND is the only person to have won BOTH the U.S. F-Open and the U.S. F-TR National Championships.
And guess what? Derek runs this kind of “opposite” bolt set-up. Yep, Derek shoots right-handed with a left bolt. Though Derek is a right-hander, he shoots with a Left Bolt/Left Port (LBLP) action. He pulls the trigger with his right index finger, while working the left-side bolt with his left (weakside) hand. This allows him to stay in position, and maintain his cheekweld. He places his right hand on the grip, while manipulating the bolt (and feeding rounds) with his non-trigger-pulling hand.
Recent F-TR World Champion and King of 2 Miles Derek Rodgers
This is the rifle with which Derek won the 2013 F-TR National Championship.
*For true standing, off-hand shooting (whether in competition or on a hunt), a conventional strongside bolt placement makes sense, since the non-dominant arm must support the front of the rifle all the time. When shooting from bipod or rest, it’s a different story.
George Gardner was kind enough to send us 50 pieces of Pre-Production Alpha 6GT brass for preliminary testing. Like the cases I formed from 6.5×47 Lapua brass, the Alpha 6GT brass will use a small rifle primer. Purchased direct from Alpha Munitions, 6GT brass is now $1.30 per case, which is comparable with Lapua 6mm Creedmoor brass, currently $120.99/100 at Grafs.com.
BRASS — The first thing you’ll find is cartridge brass choices for the 6 GT are rather limited currently. At present, the only commercial options are Hornady and Alpha Munitions. For the die-hard Lapua fans, you can technically make 6mm GT brass from 6.5×47 Lapua, however that process is very labor-intensive. 
SUMMARY — Good Cartridge with Much Potential
Oversizing cases also causes problems because the firing pin doesn’t have the length to reach the primer solid enough to ignite it 100% of the time. When you have one that is oversized, you usually have a bunch, since you usually do several cases at a time on that die setting. If the die isn’t readjusted, the problem will continue on the next batch of cases also. They will either not fire at all or you will have a lot of misfires. In a bolt action, a lot of time the extractor will hold the case against the face of the breech enough that it will fire. The case gets driven forward and the thinner part of the brass expands, holding to the chamber wall and the thicker part of the case doesn’t expand as much and stretches back to the bolt face. If it doesn’t separate that time, it will the next time. When it does separate, it leaves the front portion of the case in the chamber and pulls the case head off. Then when it tries to chamber the next round, you have a nasty jam. Quite often range brass is the culprit of this because you never know how many times it has been fired/sized and in what firearm. Back to beating it on the ground again till you figure out that you have to get the forward part of the case out.
Dave Scott explains why the Warehouse was so unique:
