Skip to main content

Make Mine A .338

Rifles in .338-caliber have long been among my favorites. I owned a Ruger Model 77 .338 Winchester Magnum years ago and developed several handloads that performed quite well. But when shooting from the bench, it kicked like a mule. A fellow member of my gun club bought a BAR chambered in .338 Win. Mag., and I helped him work up a good handload for an elk hunt. I'm pleased to report the handload and hunter successfully accomplished their mission.

Another friend traded for a .340 Weatherby Magnum with similar intentions and quickly discovered he and the Mark V's recoil weren't too compatible. We eventually traded off our rifles for who knows what. That same friend encouraged me to pursue my first wildcat-cartridge project. Paul Marquart fitted one of his precision, cut-rifled barrels on another first-generation Ruger Model 77 and chambered it for Fred Huntington's .338-.280 RCBS Improved wildcat. I've developed a pet handload that the rifle really likes. It'll routinely group three 210-grain Nosler Partitions into just over an inch at 200 yards.


Several years later, John Gallagher converted an early World War II M38 Swedish Mauser into a .338-08 scout rifle. It, too, soon proved to be a handy little package that delivered top-notch performance. A couple of years ago, Federal Cartridge domesticated the round, calling it the .338 Federal. Ruger added the new round to the Model 77 MKII's cartridge options, and I promptly ordered the Frontier model.


Soon after the recent short-magnum fad started, I rebarreled a Savage Model 16FSS Weather Warrior for the .338-.300 Remington Short Action Ultra Mag (RSAUM) wildcat. Should someone imagine I'm claiming extraordinary ballistic prowess, none of the above cartridges were my exclusive brainchild. Someone else--often several someone elses--had already done them before me. So considering my previous interests in this caliber, it's not surprising I've already latched onto the latest joint venture between Ruger and Hornady--the .338 Ruger Compact Magnum (RCM).

I received my new Model 77 Hawkeye .338 RCM rifle several weeks before the first production lot of factory ammo was shipped. Not to worry! I'd appropriated--or should I say "liberated"--some prototype factory loads and fired brass after a writer's range demonstration at this year's SHOT Show. Hornady provided a set of reloading dies but hadn't finalized any loading data. Just like with my wildcats, I was left to my own divinations for suitable recipes.




Again, not to worry. The .338-.300 RSAUM is almost identical to the .338 RCM except for the fact that the wildcat's case body is a bit larger in diameter. I measured case capacities (to the mouth) and determined the RSAUM case held about 78 grains of water, whereas the RCM case held approximately 5 grains less. I pulled out my Powley computer and determined a safe starting load for both rounds topped with 200-grain JSP bullets.


Wouldn't you know it? The computer indicated I should use the D-type of IMR powder, which is positioned between IMR-4320 and IMR-4350 on the Powley scale.

Fortunately, IMR-4007 SSC was introduced a year or so ago, and it's advertised as exhibiting a burn rate between 4320 and 4350. It was just what I needed to load the new .338 RCM cartridge.

Before I continue, let me point out that Hornady loads factory RCM ammo with what I refer to as "vanity propellants," as they are especially formulated for a limited application to provide optimum ballistic performance. That's the good news. The flip side of this situation is they aren't canistered powders that we handloaders can buy. So we're stuck with selecting from at least 15 or 20 other propellants with similarly appropriate burn rates.

So far, I've fired about a hundred rounds of factory 200-grain SSTs and my handloads. The average velocity recorded from Ruger's 20-inch barrel with the 200-grain .338 RCM factory loads was 2,850 fps. It matched the velocity printed on the cartridge box and is commendable performance in anybody's book. The handloads were charged with IMR-4007 SSC and another new Hodgdon powder, Hybrid 100V. It's supposed to be slower than H4350 and faster than H4831, which puts it even farther below IMR-4007's position on a burn-rate chart.

Topped with 200-grain JSP bullets, the loading density with either powder is nearly 100 percent. I couldn't measure pressures, but my Oehler chronograph recorded only 2,650 fps for the two .338 RCM handloads. Similar recipes but with three to five percent more powder in the .338-.300 RSAUM (with 24-inch barrel) delivered 2,849 fps, and I don't believe I'm pushing any pressure limits.

That's all for now, but I'm sure there will be more practical information about .338-caliber rifle cartridges to share with you later.

GET THE NEWSLETTER Join the List and Never Miss a Thing.

Recommended Articles

See More Recommendations

Popular Videos

Tactical Solutions Introduces New X-Ring Takedown SBR Rifle

Tactical Solutions Introduces New X-Ring Takedown SBR Rifle

Keith Feeley of Tactical Solutions sat down with Michael Bane at SHOT Show 2018 to talk about the new X-Ring Takedown SBR .22LR rifle.

The Future Of Special Operations Small Arms

The Future Of Special Operations Small Arms

We're taking a look at what the Army's Elite Units are using for service rifles and what the future of SOCOM sniping looks like.

Skills Drills: 3-Second Headshot

Skills Drills: 3-Second Headshot

James Tarr runs through the 3-Second Headshot drill.

All About .300 Blackout

All About .300 Blackout

The .300 Blackout is here to stay, and we take some time to look at new technology surrounding this cartridge. Next, we pit subsonic rivals against each other before stretching the legs of this CQB round out to 600 yards from a short 9-inch barrel.

See More Popular Videos

Trending Articles

How can a shorter-barrel revolver have higher velocities than a longer-barrel semiauto pistol? Here's why.Revolver vs. Semiauto Pistol: A Ballistic Oddity Handguns

Revolver vs. Semiauto Pistol: A Ballistic Oddity

Allan Jones - May 15, 2019

How can a shorter-barrel revolver have higher velocities than a longer-barrel semiauto pistol?...

Like situational ethics, standards of accuracy vary according to circumstances.Accuracy: It's All Relative How-To

Accuracy: It's All Relative

Terry Wieland - May 09, 2019

Like situational ethics, standards of accuracy vary according to circumstances.

Considering how popular the .270 Winchester has become, it's a great mystery why more .270 caliber (6.8mm) rifle cartridges  have not been introduced.5 Great .270 Rifle Cartridges Ammo

5 Great .270 Rifle Cartridges

Layne Simpson - May 28, 2019

Considering how popular the .270 Winchester has become, it's a great mystery why more .270...

Shooting a .22 LR rifle at 300 yards is just as challenging as shooting a .300 Win. Mag. rifle at 1,000 yards.Ruger Custom Shop 10/22 Competition Rifle at 300 Yards Rifles

Ruger Custom Shop 10/22 Competition Rifle at 300 Yards

Layne Simpson - November 13, 2020

Shooting a .22 LR rifle at 300 yards is just as challenging as shooting a .300 Win. Mag. rifle...

See More Trending Articles

More Ammo

Speer's 9mm Gold Dot CarryGun ammo is highly accurate and produces consistent velocities, extreme spreads and standard deviations.Speer 9mm Gold Dot CarryGun Ammo Ammo

Speer 9mm Gold Dot CarryGun Ammo

Joel J. Hutchcroft - November 11, 2020

Speer's 9mm Gold Dot CarryGun ammo is highly accurate and produces consistent velocities,...

Effective, efficient, and affordable, the .375 Ruger and .416 Ruger are two of the best dangerous-game cartridges around..375 Ruger & .416 Ruger — Big Bore Cartridges Ammo

.375 Ruger & .416 Ruger — Big Bore Cartridges

Joseph Von Benedikt - October 23, 2020

Effective, efficient, and affordable, the .375 Ruger and .416 Ruger are two of the best...

You asked for it, and we've responded. Here's the lowdown on the soft-shooting wildcat .41 Special.Revisiting the .41 Special Ammo

Revisiting the .41 Special

Lane Pearce - March 02, 2021

You asked for it, and we've responded. Here's the lowdown on the soft-shooting wildcat .41...

A unique load for the .450 Bushmaster is Hornady's new Subsonic offering. It's loaded with the company's 395-grain Sub-X (Subsonic–eXpanding) bullet that is designed to expand and penetrate but not break up.Hornady .450 Bushmaster Subsonic Ammo Ammo

Hornady .450 Bushmaster Subsonic Ammo

Steve Gash - August 13, 2020

A unique load for the .450 Bushmaster is Hornady's new Subsonic offering. It's loaded with the...

See More Ammo

Magazine Cover

GET THE MAGAZINE Subscribe & Save

Digital Now Included!

SUBSCRIBE NOW

Give a Gift   |   Subscriber Services

PREVIEW THIS MONTH'S ISSUE Arrow

Buy Digital Single Issues

Don't miss an issue.
Buy single digital issue for your phone or tablet.

Buy Single Digital Issue on the Shooting Times App

Other Magazines

Special Interest Magazines

See All Special Interest Magazines

GET THE NEWSLETTER Join the List and Never Miss a Thing.

Phone Icon

Get Digital Access.

All Shooting Times subscribers now have digital access to their magazine content. This means you have the option to read your magazine on most popular phones and tablets.

To get started, click the link below to visit mymagnow.com and learn how to access your digital magazine.

Get Digital Access

Not a Subscriber?
Subscribe Now