Category Archives: Performance LR Weaponry

The 338-340

Way back in the day, in my teens and early 20’s, (when Elmer Keith lived but on my bookshelf, and the likes of “Hatchers Notebook”), I was always facinated by the cartridge he called the 334 OKH. OKH stood for O’Neil, Keith, and Hopkins. The cartridge was a 375 H&H Magnum necked down to accept 0.334-inch-diameter bullets. At the time, there were still third-inch bullets being made by the British, while Barnes was the first person in the United States to do the same.

Because of Elmer Keith’s growing fame and reputation as a writer, the OKH became better known than similar developments such as the .333 Barnes Supreme, which also used the belted 375 H&H case but was also “blown out” for greater powder capacity. Even P. O. Ackley got in on the fun, and built his version of the blown-out .333 Magnum Improved his now famous 40-degree shoulder or “AI” Improved Calibers.

And then there’s Roy Weatherby, (who must have been in a conservative mood) when he passed the chance to do more of the same. Roy waited until 1963 to introduce the best of the lot; the 340 Weatherby Magnum with its very effective double-radius shoulder. It, too, is based on the 375 Holland & Holland Magnum, a belted cartridge that dates back to 1912 and is still going strong.

Why is it the best? That’s just an off-the-cuff opinion, meant to stir up a little controversy.

But I can tell you this… I’ve had more than a few 338 Lapua rifles in my hands, dating back to when they weren’t all the rage, and from my bench the 340 Weatherby Magnum consistently is more accurate in rifles of equal quality, and almost identically as powerful even though it has notably less case capacity, so the efficiency was a proven fact despite the new generation moving away from belted Magnums to that of the 300 and 338 Remington Ultra Magnums.

(those that know me also know I love my RUMS!) This being said the fact remains the 340 Weatherby Magnum is still far more efficient, belt and all and burns considerably less powder and runs much better than the .338 Win. Mag. in terminal ballistics way out to 600 yards or more.

Weatherby’s 340 came along just five years after Winchester introduced the excellent 338 Winchester Magnum, and that reason more than any other is likely the one that finally got Roy to fill the gap between his legendary 300 Weatherby Magnum and the very powerful 375 and 378 Weatherby Magnums. On paper the 378 is far more powerful than the 375 RUM and that is also a proven fact due to the radius shoulder where efficiency is born.

The 340 Weatherby Magnum rifles most often have a 1:10-inch twist, so they can stabilize the 300-grain Sierra MatchKings for target or two-legged quarry to the mighty 300 Grain Nosler Accubond Bullet for hunting 4 legged quarry…

I have found that somewhat lighter match bullets, especially the 200 and 250-grain bullets also shoot well out of my Custom TC Encore in 340 and also my Custom Remington 700 in 340 WBY Mag. I have everything from a light and handy 340 Weatherby Magnum sporting rifle in a 8 lbs. TC Encore to a 12.5 lbs. TC Encore Target Version including my 338 Lapua Magnum pulverizer the M40M1-A2 Marine Scout Sniper in 340. I got rid of all but one of my Weatherby 340’s and kept the Laser Mark Sporter. My M40M1-A2 340 will pulverize the 338 Lapua Magnum at any distance well out to 1,200 yards. Proven Fact.

They all shoot extremely well. The worst shooting 340 Weatherby I ever owned was an American-made Mark V Deluxe. It shot a little under an inch, and was beautiful but a hunter, not a shooter…

My VVCG – CBJ Precision 340 Custom .338-.340 – Custom Chamber 340 TC Encore

Some people, usually the jealous types who want but don’t own a Mark V, whine about the belted magnum case as being “outdated” or that it is chambered typically only in the MARK V Actions… (yeah, that is why I build now 100% of the Weatherby Calibers in the “BETTER” REM 700 Long Actions)… whiners on the internet prevail especially at ROKSLIDE Web Forumn where everyone is a DIY Expert Gunsmith that know ZERO about performance of long range terminal ballistics…they all claim to be experts… PERIOD!

Problem is, they simply don’t get it. Problem is the web-guys start out shooting on paper and a superior intellect, (or so they think) when they have no idea of the 340’s capability in a superior rifle to handle the performance. Fact is, the 340 will always outperform the 338 Lapua Magnum and that comes from my 40+ years of experience… and fact in building some of the fastest .338 calibers on the Planet.

What can the 340 WM really do? For starters, it is soundly more powerful and flatter shooting than the 338 Winchester Magnum, and the 338 Winchester Magnum is a wonderful cartridge. Next, no other commercial .338 caliber cartridge has more than a paper-thin advantage over the 340 Weatherby on paper, and no practical advantage whatsoever in the field. When you’re seeking the best in a light heavyweight, and you get to the 340, you’ve gone about as far as you can go and even the 338 Excaliber and 338 Allen cannot out perform the 340 Wby. Mag.

I run a 5 Port BIG BORE Brake and the 340 Wby. Mag. is as tame as a 30-06 shooting 150 grain projectiles. That is just a fact.

As far as game goes, the 340 will reach out with flat trajectory and great authority over a 300 Win. Mag., 338 Win. Mag. or 338 RUM. For Elk, Bear or Moose I tend to recommend very well constructed heavier bullets such as the Swift 275-grain A-Frame or the 300 Grain Accubond by Nosler. It will plow through muscle and bone from any angle. In Africa, Swift A-Frames are equally effective on game such as eland. For longer shots at somewhat smaller game, such as greater kudu, a 225-grain Hornady, or any of many other choices, should be just fine. I tend to recommend the 225 to 250 Grain Projectiles in the 340 for skills to the professional hunter (PH) for most all other hunting at any ethical ranges and their trophy rooms prove the fact the 340 is king of the .338 Calibers. PERIOD!

The 340 is also effective for considerably smaller game, such as antelope and the pronghorn of North America, and various deer. Most bullets just punch through with partial expansion and very little meat loss. For elk, the cartridge is a classic with 225- to 250-grain bullets.

If you wake up some morning with the overwhelming urge to shoot 225-grain bullets at 3,300 fps, as fast as 180 grainers out of most Monster 300 magnums, now you know what you need in order to pull that off. But you need it built by us! Bayou Advanced Weapon Systems, LLC.


Corey B. James

My build:

Custom REM 700 Accurized Long Action, Trued Action w/ 27″ SENDERO Contour Stainless Barrel Fluted (6 flutes), blackened spiral flutes (27″ barrel length without brake), 5R, 1:10″ Twist Rate, BIG BORE 5-port brake threaded 5/8″x24″, REMAGE NUT, Recoil Lug, .202″ Precision Ground, 338-340 Weatherby Magnum Custom Chamber — 300 Gr. AB Noslers run at nearly 3,490 FPS – built better by: Bayou Advanced Weapon Systems, LLC and CBJ Precision

My TC Encore in 340 Weatherby Magnum >>

Tract Optics


Check out

This company “gets it” … they have engineered optics for the extreme hunter and ethical long range hunter in mind with superior glass optical components that rival optics twice the cost.

Demanding and discriminating hunters will love these optics.    They are designed with the “real” hunter in mind.  The “Jon’s” at Tract, Mr. J. Allen and J. LaCorte are the “REAL DEAL” — these men are engineers that are true sportsmen and ethical individuals that have a concentric focus to the hunter and shooter.    These men also for being engineers communicate quite well to the average person or the experienced.    They have what we seek in our partners, our customers and our suppliers… “they have Ethics and Passion”… this is the #1 reason CBJ Precision LLC and CBJ Precision Engineered Rifles, Inc. is choosing Tract for our extreme hunting advanced weapon systems.

Reality is that most hunting even trophy hunt and kills occur at distances well below 300 yards in over 95% of hunts for the “average” trophy hunter.

Don’t get me wrong, everyone has their own “ethical” kill limits on game animals and personally it is more than just ethics it is an individual responsibility to know your limits and the limits of your hardware.

Furthermore, the reality is you do not need 30mm, 34mm and 35mm main scope tubes or 27-30 power (at the top-end) to shoot at extended distances of say 400-800 yards on game or non-competitive target shooting.    12-15x is plenty quite frankly for 1,000+ yard shooting and if you have a problem hitting target at that distance it is more than likely a human issue (your eyes, your hold, trigger and breathing control).    Other potential limits before you will “out grow” a 12-15 power optic is your weapons limitation in your choice of caliber, barrel and optics mounting solutions.

We have initiated an extensive and extreme test of the Tract Optics line and will be reporting our results soonest to this blog.

Thus far, the people, the company and the superior attention to detail from the owners speak volumes as to this company and their ability to compete in a wildly competitive optics market.

You simply do not need $1,500 to $3,500 optics to hunt with (in the majority of cases) and this company is about to upset that market space.

Oh and do not get me wrong, there is a need and requirement for $1,500 to $4,000+ optics — many of these high end optics are required for our custom builds and designs made for the ultimate sniper-grade, professional grade weaponry…  it is just a simple fact, they are required.

An optic solution is a tool, just like your knife or rifle….. a tool must be matched to the need, the environment, the requirement and the job at hand demands a tool that is “designed” for that fitness-of-use — you would not take a butter knife to gut an Elk right?   Well… 🙂

See the Tract Toric 3-15x50mm here!   …

See the TRACT Toric  4-20x50mm / 30mm Tube Optic right here! >>


Check out Tract Optics today!




7.62x54r – For a custom build? Are you serious?

Do not ever underestimate the power of this round.    This is considered as powerful as the 30-06 and even moderately loaded equal to the American .308 Winchester easily matching the ballistics of the 7.62 NATO/.308 Win.

Introduced in 1891, 7.62x54r ammo is the oldest cartridge still serving in military use in the world. Originally made for Mosin Nagants and other bolt-action rifles, it remains in service in Russia in the Dragunov sniper rifle and PKM machine…

The 7.62x54r is a fantastic rifle round. Developed in Russia in 1891, the 7.62x54r is sometimes referred to as the Russian 30-06 due to its similar performance and its old history.

Still used in multiple countries today, especially as a sniper, hunting, and range round, the 7.62x54r is just the proven round you want to shoot and hunt with.   This caliber is capable of taking on most North American Game and makes an excellent Whitetail and Hog caliber.

We actually chamber the REM 700 Actions in this caliber as well as our Custom Thompson Center Encore Rifle and Pistol Barrels.   Again, do not underestimate this very odd looking rimmed cartridge, the performance is what matters most and it is a most capable cartridge especially in the hands of the hand loader. 

Chambering in .308 caliber gives the designation of 7.62x53r differentiating it from the .311 bore or larger military 7.62x54r variants.   7.62x53r in .308 bore and in our custom builds easily exceed performance of the .308 Win.  We build sniper-grade 6.5mmx54r calibers as well in bolt and automatic weaponry that is highly capable and sub-MOA performers in bolt or auto.

Not a handloader?  …not a problem… Hornady, Winchester and many other factory rounds are now available due to the popularity of this round in the low-cost Military Surplus Mosin Nagant Rifle.

Still not sold on the performance?   Look here, and do your own ballistics comparisons to your favorite non-Magnum .308 calibers or even the .270 and .284 favorites you shoot.  Look at these ballistics of the 7.62x54r >> Ballistics 101