In discussions of ballistics, you’ll see references to “tangent”, “secant”, and “hybrid” bullet shapes. We know that, for many readers, these terms can be confusing. To add to the confusion, bullet makers don’t always identify their projectiles as secant or tangent designs. This article provides a basic explanation of tangent, secant, and hybrid ogive bullet designs, to help you understand the characteristics of these three basic bullet shapes.

Tangent vs. Secant vs. Hybrid
Most match bullets produced today use a tangent ogive profile, but the modern VLD-style bullets employ a secant profile. To further complicate matters, the latest generation of “Hybrid” projectiles from Berger Bullets feature a blended secant + tangent profile to combine the best qualities of both nose shapes. The secant section provides reduced drag, while the tangent section makes the bullet easier to tune, i.e. less sensitive to bullet seating depth position.

Berger Bullets ballistician Bryan Litz explains tangent and secant bullet ogive designs in a glossary section of his Applied Ballistics website, which we reprint below. Bryan then explains how tangent and secant profiles can be combined in a “hybrid” design.

How Bullet Ogive Curves are Defined
While the term “ogive” is often used to describe the particular point on the bullet where the curve reaches full bullet diameter, in fact the “ogive” properly refers to the entire curve of the bullet from the tip to the full-diameter straight section — the shank.

Understanding then, that the ogive is a curve, how is that curve described?

LITZ: The ogive of a bullet is usually characterized by the length of its radius. This radius is often given in calibers instead of inches. For example, an 8 ogive 6mm bullet has an ogive that is a segment of a circular arc with a radius of 8*.243 = 1.952”. A .30-caliber bullet with an 8 ogive will be proportionally the same as the 8 ogive 6mm bullet, but the actual radius will be 2.464” for the .30 caliber bullet.

For a given nose length, if an ogive is perfectly tangent, it will have a very specific radius. Any radius longer than that will cause the ogive to be secant. Secant ogives can range from very mild (short radius) to very aggressive (long radius). The drag of a secant ogive is minimized when its radius is twice as long as a tangent ogive radius. In other words, if a tangent ogive has an 8 caliber radius, then the longest practical secant ogive radius is 16 calibers long for a given nose length.”

Bryan Litz Explains Hybrid Design and Optimal Hybrid Seating Depths

Ogive Metrics and Rt/R Ratio
LITZ: There is a number that’s used to quantify how secant an ogive is. The metric is known as the Rt/R ratio and it’s the ratio of the tangent ogive radius to the actual ogive radius for a given bullet. In the above example, the 16 caliber ogive would have an Rt/R ratio of 0.5. The number 0.5 is therefore the lowest practical value for the Rt/R ratio, and represents the minimum drag ogive for a given length. An ogive that’s perfectly tangent will have an Rt/R ratio of 1.0. Most ogives are in between an Rt/R of 1.0 and 0.5. The dimensioned drawings at the end of my Applied Ballistics book provide the bullets ogive radius in calibers, as well as the Rt/R ratio. In short, the Rt/R ratio is simply a measure of how secant an ogive is. 1.0 is not secant at all, 0.5 is as secant as it gets.

Hybrid Bullet Design — Best of Both Worlds?
Bryan Litz has developed a number of modern “Hybrid” design bullets for Berger. The objective of Bryan’s design work has been to achieve a very low drag design that is also “not finicky”. Normal (non-hybrid) secant designs, such as the Berger 105gr VLD, deliver very impressive BC values, but the bullets can be sensitive to seating depth. Montana’s Tom Mousel has set world records with the Berger 105gr VLD in his 6mm Dasher, but he tells us “seating depth is critical to the best accuracy”. Tom says a mere .003″ seating depth change “makes a difference”. In an effort to produce more forgiving high-BC bullets, Bryan Litz developed the hybrid tangent/secant bullet shape.

For today’s Sunday GunDay story we offer a short history of the legendary .50 BMG cartridge, tips on loading, and some fun photos from FCSA matches in the Western USA.

Fans of Heavy Artillery should visit Fifty Caliber Shooters Association (FCSA) website. There you’ll find range maps, photo collections and animated slide-shows On the FCSA photo gallery page, you’ll find a map. Click on any gray range link to see images from that venue. There are also a series of articles covering FCSA competition along with the “care and feeding” of the big 50-caliber rifles.

About the .50 BMG Cartridge

The .50 Browning Machine Gun (.50 BMG, aka 12.7×99mm NATO or 50 Browning) is a cartridge developed for the Browning .50 caliber machine gun in the late 1910s, entering official service in 1921. Under STANAG 4383, it is a standard cartridge for NATO forces as well as many non-NATO countries.

John Browning had the idea for this round during World War I in response to a need for an anti-aircraft weapon, based on a scaled-up .30-06 Springfield design, used in a machine gun based on a scaled-up M1919/M1917 design that Browning had initially developed around 1900. According to the American Rifleman: “The Browning .50 originated in the Great War. American interest in an armor-piercing cartridge was influenced by the marginal French 11 mm design, prompting U.S. Army Ordnance officers to consult Browning. They wanted a heavy projectile at 2700 FPS, but the ammunition did not exist. Browning pondered the situation and, according to his son John, replied, ‘Well, the cartridge sounds pretty good to start. You make up some cartridges and we’ll do some shooting’.”

Are you a died-in-the-wool .50 BMG fan? Got a hankerin’ for heavy artillery? Then visit the FCSA Photo Gallery page. There you’ll find hundreds of photos from Fifty Caliber Shooting Association (FCSA) matches and 50 Cal fun shoots in eleven states plus Australia, Switzerland, and the United Kingdom. To access the photos from the Gallery Page, start by selecting a shooting club and state with the brown buttons. After selecting the location, then click on the colored buttons for the event date.

Photo sets go all the way back to 2002, so you can see the evolution of the hardware over the years. Sample multiple archives to see the differences in terrain from one range to another — from Raton’s alpine setting to the hot, dry Nevada desert. This Gallery is really a treasure-trove of .50-Cal history. Here are a few sample images.

Reloading Powder and Special Tools for .50 BMG

Alliant’s Powder for 50-Caliber Applications
In 2009 Alliant unveiled Reloder 50, a slow-burn-rate powder designed primarily for long-range, .50-caliber rifle shooters. According to Alliant, the burn rate is “a little slower than Winchester 860″ and the powder is showing excellent lot-to-lot consistency. Load density is optimized for the 50 BMG and similar cases. Like Reloder 17, Reloder 50 employs a process which penetrates the kernels with the burn-rate-controlling chemical. This should allow a longer, flatter pressure curve, yielding more velocity than conventional powders can deliver. Alliant says that Reloder 50 offers “superior velocity and the ability to burn cleaner (with less residue)”. Reloder 50 comes in both 1-lb (#150527) and 8-lb (#150528) containers.

Forster and Lyman .50 BMG Trimmers
Big Fifty enthusiasts asked for a dedicated .50 BMG case trimmer, so Forster and Lyman created .50 Cal trimmers specifically for that cartridge. The cutter tip on the Forster .50 BMG Case Trimmer is much sharper than the cutter on the Lyman 50 Cal AccuTrimmer. However, the Forster tool is currently out of production, so it is harder to find than the Lyman .50 BMG trimmer, which is $92.93 on Amazon. Our advice is go ahead and get the Forster if you can find one — the cutter head is much sharper, and we prefer the Forster’s collet-style case-holder. The Forster gets the job done more quickly, with less effort. If you want the ultimate .50 BMG trimmer, check out the L.E. Wilson .50 BMG trimmer. But it is a hefty $268.40 at Midsouth.

Giraud .50 BMG Case/Bullet Comparator
Giraud Tool makes a comparator for 50-Cal cartridges. The double-ended comparator is quite versatile. In one orientation you can measure base-to-ogive bullet length and also measure cartridge OAL from rim to bullet ogive. When reversed, you can use the comparator to measure cartridge headspace. The $35.00 Giraud .50 BMG Comparator gauge is constructed of 303 stainless and fits most any vernier, dial, or digital caliper. CLICK HERE for more info.

Will you be heading to the varmint fields this summer? Proper planning is key to a safe, satisfying, and productive varmint holiday. Bring a variety of rifles if possible — you’ll need to switch off as one barrel gets hot, and the chambering that works best for your close shots may not be ideal for those longer shots out past 400 yards. Here’s one tip that can help you shoot more effectively on your varmint hunt — at your shooting station, put a strip of surveyor’s tape on a tall stake to show the wind direction. Then align to the wind direction, so that it is a direct headwind or tailwind. This will minimize the effect of cross-winds.

For fans of varmint hunting, we’ve assembled eight videos for this Saturday at the Movies Feature. You’ll see a variety of rifles being used in classic American varmint country — Montana, Oregon, and the Dakotas. We’ve also included an interesting video from South Africa.

Extreme Outer Limits — Oregon Adventure with .22 Creedmoor

This varmint safari video features the Extreme Outer Limits squad in Central Oregon. The host is shooting the .22 Creedmoor cartridge from a 22″ Benchmark barrel. The shooters benefit from a great operation, with elevated mobile shooting stations and benches. Watching this video made this Editor want to travel up to Oregon this summer, and try out a .22 Dasher that’s been sitting in the safe.

This video has plenty of action, with hits on small varmints (mostly ground squirrels) out to considerable distances. You can see the effectiveness of the .22 Creedmoor cartridge — it basically vaporizes some of the critters.

.22-250 Nails Ground Squirrels and Rock Hyraxes in South Africa

Here’s an interesting video from South Africa. The video maker starts with shots on ground squirrels. His .22-250 blasts them into little pieces. They he switches to more distant targets, a furry ground-hog size animal called the Rock Hyrax, Cape Hyrax, or Dassie. Mature Rock Hyraxes weigh 4-5 kilograms and have short ears and tail. These Rock Hyraxes are found at higher elevations in habitats with rock crevices, allowing them to escape from predators (but not skilled varmint hunters).

1125-Yard Rockchuck Hit with Extreme Outer Limits

Here a team from Extreme Outer Limits tests their skills at Extreme Long Range Varminting. The group set up benches and aim their rifles at a distant hillside over 1100 yards away. You can see a successful first-shot rockchuck hit at the 5:15 time-mark. On this episode of Extreme Outer Limits, Bob Beck, Tim Titus, and some MOA Rifles clients to put the .22 Creedmoor and other MOA-brand rifles to the test. At these long distances, Rockchucks are relatively small targets providing plenty of challenge.

Long Range Rockchuck Adventure with Gunwerks Crew

This Gunwerks video showcases varmint hunting in the Western USA. In this video Aaron Davidson and the Gunwerks crew try out some new rifles on some rockchucks. Most of the the rifles were suppressed but the host said the rockchucks took cover after the first shot, so this required good coordination among shooters and spotters. A 6XC varminter is featured at 2:44 and there’s some nice drone footage starting at 2:00.

Varminter.com — Great Resource for Varmint Hunters

Varminter.com is a great resource for serious varmint hunters. This site regularly reviews rifles, optics, and varmint ammunition. In addition, the site’s founder, Eric Mayer, often ventures out in the backcountry to film his varmint adventures.

Varminting with .17 HMR Savage A17 and Custom .17 WSM AR

On varmint excursions, we like to have a .17 rimfire for the closer shots, inside 150 yards. This video shows a successful Prairie Dog hunt with a .17 HMR. Watch and you’ll see hits out to 160 yards (00:50), proving the effective range of the .17 HMR cartridge. The host is shooting a Savage A17 semi-auto 17 HMR rifle in a Boyds laminated stock.

Varminters now enjoy three .17-caliber rimfire options. The .17 Mach 2, .17 HMR, and .17 WSM are all good choices, with the 17 Mach 2 being the cheapest and the .17 WSM the most powerful. With a rimfire you save on ammo costs and you don’t waste precious centerfire barrel life. Also the noise is reduced so you don’t spook the critters so much. We have shot ground squirrels with both the 17 HM2 and .17 HMR. And with a 3000 fps MV, the .17 WSM has some really impressive ballistics. As you can see, the .17 WSM has a much flatter trajectory than both the .17 HMR and .22 WMR:

Last but certainly not least, this video from Eric Mayer, founder of Varminter.com and AR15Hunter.com. This video features an innovative AR-platform rifle chambered for the potent .17 Winchester Super Magnum (aka .17 WSM) cartridge. Eric was able to have instant kills out to 200 yards. This rifle features a Franklin Armory F-17 V4 upper with a Franklin Armory 10-rd magazine. Eric was very impressed with the .17 WSM and he believes the 20gr bullet with 3000 fps MV will be very effective for most of his small varmint hunting out to considerable distances.

KILL Shots — BONUS Age-Restricted Videos

Linked below are a couple very good varminting videos that show explosive hits. However, YouTube has decided these can’t be posted on third-party websites so you’ll have to click the links below to see the Prairie Dogs going airborne. In the first video, the lady shooter nails THREE P-Dogs with one shot!

1. Eastman’s Hunting Journals. Great Video from Eastern Montana. This has nice Aerial Footage and an amazing shot with three P-dogs (in line) dropped with a single shot (at time-mark 9:28). One shot — THREE prairie dogs down! This prairie dog hunt features slow-motion kill shots, digiscope close-ups, and a rare prairie dog triple kill. A group of hunters works to remove prairie dog pests from private grazing lands in this episode of Beyond the Grid by Eastmans’ creators of Eastmans’ Hunting TV. You’ll have to CLICK HERE to watch this video. See Also Eastman’s Prairie Dog Armageddon video.

2. Flying Prairie Dogs in North Dakota. You’ll see some impressive kill shots made with AR-platform rifles in this short (2-minute) High Road Hunting video from Keith Warren Hunting YouTube channel. See also Keith’s Prairie Dog Hunting Shooting Spree video.

Bix’n Andy Savage TacSport Pro X and Savage Dakota Triggers

Article based on review by Les Voth

In 2012 benchrest shooter Chris Harris, owner of BulletCentral.com, brought Austrian gunsmith and engineer Andy Atzl’s Bix’n Andy triggers to America. Since then, their collaborative innovation has not slowed or stopped. Well known to the benchrest world, the Bix’N Andy Remington 700 Competition trigger with its frictionless ball trigger design, has broken records and surpassed previous trigger designs what came before The mechanism that replaced friction designs has gained favor among their shooters who have Bix’N Andy triggers on their rifles

Seeking to go beyond providing triggers for Remington 700s, Rem 700 clones, Tikkas, Sakos, and Barnards, BulletCentral.com now offers atop-quality, drop-in Bix’n Andy replacement triggers for the Savage 110 line of rifles. As these popular Savage rifles are offered in many configurations, including competition rifles, hunting rigs, and varmint rifles, it made sense to offer a top-quality Bix’N Andy trigger for Savage rifles.

Bix’N Andy Savage Trigger Review — UltimateReloader.com

In my association with Bullet Central, as their trigger repair and warranty guy, I’ve already seen these new Bix’N Andy Savage triggers installed on competition single shots, prairie dog rifles, truck guns, deer/hog hunting rifles, and varmint rifles. The appreciation shown by their new owners, for having access to the same technology as the most expensive ELR, PRS, F-Class rifles is great to witness.

Installation in Savage Action is Fast and Easy
Changing the trigger on a Savage 110 is as simple as removing the stock, pulling one pin to remove the stock trigger, and putting the new trigger in its place with the return of the pin.

Savage Tacsport Pro X (3.5 oz to 2.2 lbs) | Savage Dakota (1 lb. to 4.4 lbs.)

The Savage TacSport Pro X trigger has a pull force weight range from 3.5 ounces to 2.2 pounds, and the Dakota model starts at one pound and goes up to 4.4 pounds. With the TacSport Pro X model you can change the shoe, from curved, to straight, to the Gator grip shoe, without disassembling the trigger.

When using a Bix’n Andy Savage trigger for the first time, you’ll instantly sense how it precise and smooth it feels. Because you are not trying to “overcome” something with the trigger force it is set at. You’ll note that the movement feels smoother than a friction-based trigger (with the same pull weight).

When you set a trigger to your desired pull force, whether it is under 10 ounces, or over two pounds, the Bix’n Andy trigger will feel lighter than the others because of its inner mechanism. You are not trying to “overcome” you are “setting off” the trigger, if that’s how to describe it.

Also, when some triggers release the cocking piece, they stop at a wall. Bix’n Andy triggers do not. They follow through with slight over-travel, so the rifle is not upset during that time the bullet has not yet exited the barrel. This is a feature that the Bix’n Andy Savage TacSport triggers and also the Dakota share with the original Benchrest triggers from the same company.

Benefits of Trigger Replacement in Savage Rifles
Why would you replace the stock trigger on a Savage 110? Well, it’s like Chuck said on Friday when he came to pick up a truckload of prairie dog pills – “If yer gonna git serious about shooting prairie dogs, yer gonna change triggers!” Who’s Chuck? He’s a retired Vietnam vet/volunteer NRA Range Officer. When asked how many prairie dogs he shot on his last trip, he said “…about 400.”

That many trigger pulls demand a trigger that works, one that doesn’t distract you from the job at hand, and one that allows you to shoot little targets a long ways away.

F-Class ace Erik Cortina has interviewed noted author and Olympic Gold Medal-winning shooter Lanny Bassham. For his popular video channel, Cortina asked Lanny about his book With Winning in Mind. The two talented shooters also broadly discussed the “mental game” in the shooting sports and Lanny’s program for visualization of a winning performance. Lanny explains that after you have mastered your rifle skills, and learned to read the wind, it is important to adopt a winning mentality and to visualize success. Lanny should know. He won a shooting Gold Medal in the Olympics along with 22 world individual and team titles.

Watch Full Video Interview
Here is the wide-ranging and fascinating hour-long Lanny Bassham interview hosted by Erik Cortina. If you are looking to enhance your motivation, discipline, and “mental focus” when competing, this video is worth watching:

With Winning in Mind — About the Book

With Winning in Mind (3rd. Edition)
by Lanny Bassham, $9.99 (Kindle), $16.95 (Softcover)

Visualization is a process of mental preparation that is done before you get to the range. Many of the greatest shooting champions have used this technique to get ready for big matches, and to optimize their performance during record fire. If you want to enhance your “mental game” through pre-match visualization, we strongly recommend Lanny Bassham’s book, With Winning in Mind.

As a competitive smallbore 3P shooter, Bassham developed a mental management system. Using this system, Lanny Bassham won 22 world individual and team titles, set four world records, and captured an Olympic Gold Medal in Montreal in 1976. His techniques have been embraced by professional and Olympic athletes in many sports. With Winning in Mind covers a complete system of “mental management” techniques used by Olympians and elite champions.

Putting principles into practice — Anette Wachter

Our friend Anette Wachter, aka “30CalGal”, did a series of videos for the NRAWomen.com site. In one episode, Anette talks about the “mental game” in competition. Specifically she explains how to “visualize success”:

I have found that a lot of my success in competition has come through what I call a ‘mental rehearsal’. I actually visualize every stage of the match and I visualize the success of the match and winning the match.

I actually visualize that round going downrange into the target, and the target coming up with a dead-center ‘X’. I visualize this over and over. If you visualize success you will achieve success.

Guest Article By Michelle Gallagher, Berger Bullets
Let’s face it. In the world of firearms, there is something for everyone. Do you like to compete? Are you a hunter? Are you more of a shotgun shooter or rifle shooter? Do you enjoy running around between stages of a timed course, or does the thought of shooting one-hole groups appeal to you more? Even though many of us shoot several different firearms and disciplines, chances are very good that we all have a favorite. Are we spreading ourselves too thin by shooting different disciplines, or is it actually beneficial? I have found that participating in multiple disciplines can actually improve your performance. Every style of shooting is different; therefore, they each develop different skills that benefit each other.

How can cross-training in other disciplines help you? For example, I am most familiar with long-range prone shooting, so let’s start there. To be a successful long-range shooter, you must have a stable position, accurate ammunition, and good wind-reading skills. You can improve all of these areas through time and effort, but there are other ways to improve more efficiently. Spend some time practicing smallbore. Smallbore rifles and targets are much less forgiving when it comes to position and shot execution. Long-range targets are very large, so you can get away with accepting less than perfect shots. Shooting smallbore will make you focus more on shooting perfectly center shots every time. Another way to do this with your High Power rifle is to shoot on reduced targets at long ranges. This will also force you to accept nothing less than perfect. Shoot at an F-Class target with your iron sights. At 1000 yards, the X-Ring on a long range target is 10 inches; it is 5 inches on an F-Class target. Because of this, you will have to focus harder on sight alignment to hit a center shot. When you go back to the conventional target, you will be amazed at how large the ten ring looks.

Also, most prone rifles can be fitted with a bipod. Put a bipod and scope on your rifle, and shoot F-TR. Shooting with a scope and bipod eliminates position and eyesight factors, and will allow you to concentrate on learning how to more accurately read the wind. The smaller target will force you to be more aggressive on your wind calls. It will also help encourage you to use better loading techniques. Nothing is more frustrating than making a correct wind call on that tiny target, only to lose the point out the top or bottom due to inferior ammunition. If you put in the effort to shoot good scores on the F-Class target, you will be amazed how much easier the long-range target looks when you return to your sling and iron sights. By the same token, F-Class shooters sometimes prefer to shoot fast and chase the spotter. Shooting prone can help teach patience in choosing a wind condition to shoot in, and waiting for that condition to return if it changes.

Benchrest shooters are arguably among the most knowledgeable about reloading. If you want to learn better techniques about loading ammunition, you might want to spend some time at benchrest matches. You might not be in contention to win, but you will certainly learn a lot about reloading and gun handling. Shooting F-Open can also teach you these skills, as it is closely related to benchrest. Benchrest shooters may learn new wind-reading techniques by shooting mid- or long-range F-Class matches.

Position shooters can also improve their skills by shooting different disciplines. High Power Across-the-Course shooters benefit from shooting smallbore and air rifle. Again, these targets are very small, which will encourage competitors to be more critical of their shot placement. Hunters may benefit from shooting silhouette matches, which will give them practice when shooting standing with a scoped rifle. Tactical matches may also be good, as tactical matches involve improvising shots from various positions and distances. [Editor: Many tactical matches also involve hiking or moving from position to position — this can motivate a shooter to maintain a good level of general fitness.]

These are just a few ways that you can benefit from branching out into other shooting disciplines. Talk to the other shooters. There is a wealth of knowledge in every discipline, and the other shooters will be more than happy to share what they have learned. Try something new. You may be surprised what you get out of it. You will certainly learn new skills and improve the ones you already have. You might develop a deeper appreciation for the discipline you started off with, or you may just discover a new passion.

Hodgdon Powder Company (Hodgdon) offers a series of informative, “how-to” instructional videos through its online Reloading Data Center. These 3.5-minute videos present rifle, pistol, and shotshell reloading basics in an easy-to-understand, step-by-step format. These mobile-friendly, informative videos can also be viewed on a smart phone or tablet.

To watch the reloading videos go to the Reloading Data Center at hodgdon.com. Click to the right/left of the displayed video to switch between pistol, rifle, and shotgun videos. Or, for your convenience, we have embedded the Rifle and Pistol videos here. Just click to watch!

Click to Watch Hodgdon Rifle Reloading Video:

Click to Watch Hodgdon Pistol Reloading Video:

In addition to these videos, Hodgdon’s Reloading Data Center (RDC) provides a wealth of information on Hodgdon, IMR, Accurate, Winchester, and Ramshot propellants. Along with reliable load data, you’ll find explanations of reloading basics, safety procedures, plus answers to frequently asked questions (FAQ).

Our friend Robert Whitley of ARX Enterprises LLC has learned, through careful measurement and testing, that some barrels threaded 5/8″ x 24 TPI at the muzzle may not deliver optimal accuracy. The reason is that the end of the barrel can bell out slightly, like a trombone, because too much steel has been removed. This is particularly true with .30-caliber barrels, but it can also be a problem with smaller caliber barrels (even 6mm). Robert demonstrates this phenomenon in the video below. All gunsmiths, and anyone considering threading a barrel, should watch the video. At 1:00 – 1:30 Robert gauges a 5/8″ x 24-threaded .30-Caliber barrel. You can see the belling effect clear as day.

“When setting up a commercial barrel in the lathe, we noticed that the maximum-sized bushing that would fit in the bore at the chamber end was almost .0015” smaller [than what would fit] at the muzzle. That precipitated my pin-gauging of a number of different commercial barrels that were threaded for 5/8” x 24 tpi. What I found is what’s shown on the video.” – R. Whitley

Solve Problem with a Larger Thread Diameter
If 5/8″ x 24 threading is potentially harmful to accuracy, is there a solution? Yes, you simply need to leave a little more steel on the barrel. (See Video starting at 02:40.) Frank Green of Bartlein barrels states: “We get these questions all the time. I say run the largest thread diameter that is possible.” Robert Whitley has found that a 3/4″ x 28 TPI threading does not cause the “belling effect”. Accordingly Robert recommends 3/4″ x 28 if you need to thread your barrel for a muzzle brake or suppressor. Robert explains: “We only make 3/4” x 28 TPI muzzle brakes and that’s what we recommend to customers.”

“See how much meatier the 3/4″ threading is vs. the 5/8″. The 3/4″ threading offers a lot more metal around the bore. There’s a lot less opportunity for the bore to become bell-mouthed…” – Robert Whitley

Barrel Threading Diameter — What’s Important to Know

By Robert Whitley
In truth, the 5/8″ x 24 TPI threading never came out of any accuracy-based think tank or set-up, it’s a military .30-Cal threading for barrels that someone has to carry around (they needed to keep the barrel weight down so it was smaller in diameter and the threading had to work with that situation). People have somehow assumed because the military uses that threading for certain things that it must mean that it’s also fine for a highly accurate rifle too, but that’s not really correct.

I don’t think there is any better and realistic option than the 3/4″ muzzle threading, and we also do it so there is no relief cut behind the threads on the barrel (i.e. put the relief cut on the brake or jam nut, don’t chop down on the muzzle of the barrel). For some reason many have a hard time grasping that the metal at the muzzle end of a rifle is “sacred” and you should not cut it down any more than absolutely necessary. A little threaded pencil diameter nub on the end of a barrel is not ideal for accuracy especially if it’s threaded and you need to torque on it. I cringe when I see a barrel with something like an MTU or Heavy Varmint contour, only to have an itty-bitty pencil thin threaded nub right at the muzzle so someone can “screw on a can” or a muzzle brake.

Lessons Learned Over the Years
A number of years ago I did a 30BR rifle project with Craig Kostyshyn who was big in the 30BR game and he made some of the best 30BR rifle barrels for benchrest competition. When I did the project I wanted a medium-heavy Palma type contour barrel I could use and also have a muzzle turndown for a front sight band. When he found out I was going to have the muzzle turned down he said “whoa, I need to provide for that when I make the barrel because if you turn the front down later you’ll be shooting a trombone” (i.e. the muzzle bore dimension would open up).

What he did was rough contour the barrel with the turndown (about .010” oversize) before he lapped the barrel, then when he lapped the barrel he took it easy in the muzzle area and worked the back of the barrel more. I thought he was a little bit excessive in his concerns but the barrel shot great and I wasn’t going to argue with him, after all he was shooting groups in the ones. I kind of just filed that away and never thought about it until recently when I went to have Fred from Sabreco do some chamber re-work on a commercial .30-caliber barrel I had. When setting up the barrel in the lathe and indicating things Fred noticed that the maximum-sized bushing that would fit in the bore at the chamber end was almost .0015” smaller [than what would fit] at the muzzle and he mentioned it to me. That precipitated my pin-gauging of a number of different commercial barrels I had that were threaded for 5/8” x 24 TPI. What I found is what’s shown on the video.

NOTE: This is a copyrighted article. Do not reproduce or re-link more than 75 words without written permission from AccurateShooter.com.

This Sunday GunDay story celebrates an impressive victory by Raymond (“Ray”) Gross, one of America’s most skilled marksmen and a top team coach. Ray has mastered many disciplines including Service rifle, Palma rifle, and F-Class (both F-TR and F-Open). Recently Ray notched another notable victory at the CMP’s 2026 National Matches at Camp Perry, Ohio, winning the Kerr Memorial Match (Palma Rifle division).

Report by Ray Gross
I had a successful trip to Camp Perry this year, winning the Palma Rifle division of the 1000-yard Kerr Memorial Match and winning two Golds and a Silver coaching in the three team events. This is actually my first time back at Camp Perry for Long Range since 2015. I really enjoyed my time there this year.

For the Kerr match, I used my standard Palma rifle. My Barnard action and Master Class / Robertson stock have been with me for 21 years now and have seen numerous barrels and a few upgrades to the stock. The stock has a bedding block and originally I had two Barnard actions that I would swap in and out. I currently use the standard Barnard P Trigger, set to 1.5 kg.

This rifle has a Warner rear sight with true 1/4 MOA clicks. It is fitted with a Gehmann 530-0 rear diopter. The front sight is a Doug Beach 22mm ladder sight with a Centra 5.0-7.0mm adjustable aperture. For my eyesight (-2.75 x -0.75 in my aiming eye), I will generally run 5.1 to 5.6 on the 1000-yard target. At that size, I am more or less cutting the corners off the 6×6 target. Most of the ranges I shoot at have a large, dark-colored safety berm behind the target.

Camp Perry has a rather unique sight picture at 1000 yards, with the target surrounded on three sides with open sky, but with the dark pit safety berm below. It took a little bit to get used to that. The dark pit berm was prominent inside my aperture, even when turned down to 5.0. Next year, I plan to swap out the from aperture to allow me to get down to about a 4.7-4.8mm size.

The barrel is a Bartlein 5R 300×308 Light Palma taper. Chad Heckler of 5×5 Precision chambered this barrel for me. I recently troll-posted some bore pics on Facebook of this barrel at about 750 rounds. I work at Manson Reamers primarily as a chamber designer and tech support role and get to hear many stories about chambers and barrels. I think a lot of people really misjudge what they are seeing with borescopes causing a lot of worry and anxiety. The real measure of a target rifle is how it performs in competition.

Leaving Camp Perry it has about 1500 rounds down the tube and is shooting plenty good enough to win at the National Championships. By the way, I showed up with about 30 rounds fired since the previous thorough cleaning and did not clean once while there. I am not necessarily recommending that, but this barrel shoots fine dirty.

I am on my 16th firing of the Lapua large primer .308 Win brass. I have a bunch of new small primer brass that I want to use, but the lot I have been using just won’t wear out, so I keep reloading it. My Perry ammo was loaded with Vihtavuori N150 powder, but I started the year with N140 to use up that particular jug of powder. My bullet of choice for long range with the Palma rifle is the Berger 155.5 gr FullBore Target Rifle bullet seated about .035″ off the lands. Editor: The video below provides a comparison of Lapua large primer .308 Win brass vs. Lapua small primer .308 Win brass.

Most of my recent Palma barrels have the Manson 308 Win 2019 Fullbore T30 chamber (that I designed). That is a very widely-used chamber designed to pass Bisley Rule 150 inspection. It is a ‘Bisley Reamer’. Bisley reamers tend to have fairly long throats. I have a collection of various ‘Bisley Reamer’ prints from all over the world. The Manson 2019 Fullbore T30 is not the longest, but it is among the longer throated designs. SEE Diagram below (click to zoom):

CLICK reamer diagram to load full-size, downloadable .PDF file.

Since 2019 I have had a number of competitors request a shorter-throated chamber in hopes of achieving higher velocities with the NRAUK Bisley issued ammo, currently made by GGG*. The issue ammo is essentially old school Palma ammo with a Sierra 2155 seated to 2.80″ COL. The Sierra 2155 is a very accurate bullet, but it does not have the BC of more modern 155gr designs. I love shooting them at 300 and 600 yards. If you want to learn to read the wind, practice with them at long range.

The chamber in this rifle is a ‘prototype’ shorter-throated reamer designed with the help of Brandon Green and measurements of the GGG 2025 issued ammo*. The reamer is the GGG25 reamer. On the print I have a big disclaimer that the chamber probably will eventually fail the rule 150 test as bullets change over the years, but it did pass with the 2026 issued ammo. My recommendation is to stick with the 2019 Fullbore design if you plan to go to Bisley.

Here is Ray shooting his Palma rifle at Winnequah Gun Club Range in Lodi, Wisconsin.

Ray Gross Marksmanship/Coaching Biography
Ray’s shooting career began early in life hunting with his Dad. He began competing in NRA matches in 1991 as a Service Rifle shooter and earned a place on the Michigan Rifle team in 1993 and 1994. He earned his Distinguished Rifleman’s Badge in 1995 and began competing in the Palma class that year.

Ray has represented the USA as a Shooter or Coach on two Palma teams, two Australia Match Teams, and eight America Match teams. He has been the winning team coach on numerous events in Canada and the USA over the last decade. His international accomplishments include a Silver medal as a shooter on the 2003 U.S. Palma Team, a Silver medal as coach on the 2015 U.S. Palma Team, two Gold medals as a coach on the 2008 and 2014 U.S. America Match Team. The 2014 team set a new record for team aggregate score. He was Captain of the 2016 Gold medal America Match F-Class Team.

In F-Class, he was the F-TR individual Silver medalist at the first F-Class Nationals in 2004 and has coached the F-TR National Championship Team squad in 2004, 2008, 2011, 2012, 2014 and 2016, the latter five as part of Team Sinclair.

Today we showcase seven videos from video producer, skilled marksman, and Forum Member F-Class John. A talented F-Class competitor (and past Mid-Range National Champion), John analyzes product features with a smart, technically-focused mind. John has created hundreds of videos about reloading and precision tools, along with rifle and shooting accessories. And John also has created many videos showing how to improve your rifle handling and wind-calling. Many of John’s product review videos are very detailed and thorough. You’ll find over 920 informative videos on F-Class John’s popular YouTube Channel.

SEE ALL F-Class John YouTube Videos HERE »

Basics of Bullet Seating Lengths — Jump vs. Jam

Many folks getting started in the cartridge reloading game are not fully familiar with seating depth options. They may only be looking to achieve a listed Overall Length (OAL) from base to bullet tip. But, for optimal accuracy and safe functionality, you need to look at the position of the bullet’s ogive relative to the start of the barrel’s rifling (i.e. the point where bullet jacket contacts the barrel rifling). Before you start reloading you want to measure the distance to the lands. Then, for most applications you want to start with the ogive’s contact point at least .010″ or more back away from the lands — that is called “jumping”.

For some benchrest applications you may want to actually have the bullets seated longer so the bullet actually contacts the lands. That is called “jam” seating. But there are variations in that. There is both a “mild” jam — a few thousands into the lands — as well as a full jam where the bullet is seated very long (and may even push back if case neck tension is light). Be very cautious with a full jam as this can significantly increase case pressure.

How to Improve Accuracy

In this video, F-Class John explains some key techniques on optimizing match ammo. He explains how to get very precise powder loads. In the video he respond to multiple questions from his Patreon subscribers. One topic is how to avoid the outliers in a 10-shot group. If those “flyers” are consistently coming at the end of a long string, John explains the problem is not likely the ammunition. Rather it could be a variety of factors such as “driver fatigue”, wind changes, barrel heating or other issues. For competitive shooters, this video is worth watching start to finish.

Patriotic July 4 Accuracy Target

The USA’s 250th birthday is behind us, having been celebrated on July 4, 2026. In this video F-Class John shows a fun 5-star red, white, and blue patriotic target and explains some of the challenges in getting an optimal score. There is a black bull inside the center star. Another feature of this target is that you can use the points on the stars to precisely aim your cross-hairs. This is a good target for centerfire at 100 yards, rimfire at 50 yards, and handguns at closer ranges.

Rear Bag Filling — Tips for Best Results

In benchrest and F-Class disciplines, you need a good rear bag to optimize accuracy and scores. A quality rear bag both supports and stabilizes the rifle and helps the rifle track properly during recoil. To get the best, most consistent performance from rear bags, you need to optimize the fill. In this video F-Class John discusses fill options and shows the process to fill your rear bag properly. He also talks about notable bag features including bag weight, footprint, and ear height/material.

Budget-Priced Arken EPL-4 Scope That Performs Well

Top competitors may spend $2500 or more on a top-quality, high-magnification rifle scope. But for those on a tighter budget, the Arken EPL-4 offers pretty impressive performance for under $350.00. In this video John tests this optic from the bench and shows that it has good glass and functions well. The EPL-4 combines Japanese ED glass with illuminated VPR or VHR FFP reticles. The Arken EPL-4 is offered in two sizes: 4-16x44mm ($299.99 at MidwayUSA) and 6-24x50mm ($329.99 at MidwayUSA).

Advanced AMP Press for Precision Bullet Seating

The AMP Electronic Bullet Seating Press is a state-of-the-art bullet seating press that tracks seating force round by round. The AMP Press combines a motor driven ram, a distance sensor, and a load cell to deliver extremely accurate and precise bullet seating measurements. It is designed for use with inline bullet seating dies. With this press you can quickly and easily change seating depths, which is useful during load development. In addition, the AMP press outputs data from the seating process to a linked computer. This allows you to see if there is an unusual seating value. You can mark those “outlyer” rounds and use them for fouling or warm-up shots.

F-Class Front Rests Reviewed

This is a great summary of multiple quality front rests. This is a must-watch video for all F-Open and Benchrest shooters! If you are shopping for a front rest, definitely watch this comprehensive 42-minute video from start to finish. This is probably the most informative video about premium shooting rests available on YouTube. Top F-Class shooter and video-maker F-Class John covers a wide selection of front rests, with some observations about coaxial bipods as well. John covers the impressive new SEB NEO-X, the easy-to-transport SEB Mini-X, the excellent Rodzilla Rest, the innovative 21st Century Hybrid Rest, the sleek Italian Lenzi Rest. At the end of the video John reviews the very affordable Caldwell Fire Control Rest ($289.99 at MidwayUSA), explaining how it can be a decent choice for shooters on a limited budget.