Ammunition

Why Bother Inventing New Calibers? A Case for the New Cartridge.

338 Spectre cartridges in a 6.8SPC magazine

We often scoff at the new chamberings offered by ammunition manufacturers. “Solutions to nonexistent problems” we say. Sometimes, that is true. More often, the puzzling profusion of the new offerings has to do more with legal regulations than with performance – 45GAP and 9×21 are the prime examples of such developments. They were brought up to approximate the performance of 45ACP and 9×19 Luger without being prohibited military ammunition.

At other times, flatter trajectory combined with lower recoil are the goal. 25-06 and 7-08 are such derivations from 30-06 and 308 respectively. Yet another reason for new cartridges is the use in different style of firearm. For example, 45 Auto Rim adapted 45ACP to revolver use without requiring moon clips. 458SOCOM provided 45-70 Government and 450 Marlin performance in a smaller package adaptable to the low-recoil AR15 platform.

Sometimes, the logic of introducing apparently competing cartridges of similar dimensions and performance isn’t very obvious. 9mm Luger, itself derived from 7.65mm Luger by necking up to increase payload, competed against 9mm Steyr, Glisenti and Mauser. The Luger cartridge won mainly on technical merits, though being the first out of the gate also helped.

338 Spectre cartridges in a 6.8SPC magazine
338 Spectre cartridges in a 6.8SPC magazine

Recently, we’ve seen a similar profusion of short 30-something caliber cartridges crowd into the realm previously occupied by 7.62×39 Russian and .300 Whisper. Neither of those rounds is a great fit for the AR15, and so alternatives were developed. These new rounds, mainly 300 Blackout and 338 Spectre, both try to improve on the existing rounds while preserving maximum compatibility with .223 Remington and 6.8mm SPC.

300 Blackout is a clever design that fits 30 7.62mm cartridges into a standard .223 magazine. With more than double the bullet weight of the .223, it is notably more effective and equals the AK cartridge in effect. With shorter rifles and sound suppressors becoming more popular, it promotes reliability by having the same gas port pressure in standard and subsonic loads. In effect, it approximates both the 7.62×39 Russian and the dedicated subsonic 9×39 Russian, though with a smaller, lighter bullet.

Designed to fit 25 rounds to a standard 6.8SPC magazines, 338 Spectre is optimized around subsonic performance, though it also offers a number of high-velocity supersonic loads. Slightly inferior to 300 Blackout in supersonic performance, 338 beats it and the Russian 9×39 decisively in suppressed use. Since the muzzle velocity is limited by having to stay under the speed of sound, this cartridge uses extremely heavy bullets. 300BLK tops out at 220 grains, 9×39 at 250, while 338 Spectre launches 300 grain low-drag projectiles. Having by far the greatest sectional density, it also retains velocity and energy much further downrange. That extra punch means superior penetration, a useful feature in the day of ubiquitous body armor. 338 Spectre is a lower pressure cartridge than 300BLK by design, so instead of requiring a dedicated rifle sound suppressor, it can utilize much lighter and smaller 9mm pistol suppressors.

When new ammunition designs come out, it’s difficult to predict which rounds will become and remain popular. The much-maligned 40S&W is popular despite the naysayers, while initially lauded 44 Automag is long gone. Given the financial and technical hurdles in introducing new chamberings, it is not surprising that the most promising rounds have a number of compelling reasons behind their introduction. Not all of these reasons are obvious, but they do exist.

About the Author:

Oleg Volk

Oleg Volk is a creative director working mainly in firearms advertising. A great fan of America and the right to bear arms, he uses his photography to support the right of every individual to self-determination and independence. To that end, he is also a big fan of firearms.
The Mission of Cheaper Than Dirt!'s blog, The Shooter's Log, is to provide information—not opinions—to our customers and the shooting community. We want you, our readers, to be able to make informed decisions. The information provided here does not represent the views of Cheaper Than Dirt!

Comments (11)

  1. I would agree that a .338 with a 300 gr. bullet at less than the variable speed of sound would kick the sneakers off the 208 gr. .300BLK. The problem, as I see it, is that what makes a great suppressed round also make for lousy “high-velocity supersonic loads” (WTF editorial oversight) due to the bore size and the whole ballistic coefficient conundrum. To put a finer point on it; you can’t have both and one must compromise. This is very much a niche cartridge and as such it will have a tough time being remembered 5 years from now.

  2. Rather than change the whole frame of the small-frame revolvers to something smaller (the Scandium ones are at 12 oz or so, isn’t that light enough?), why doesn’t someone tool up to change only the cylinder and indexing so it will shoot more rounds? A 7 or 8-shooter in .327 Federal might just sell the round to more people, then a lever gun might be feasible, then the cartridge will have permanency. Or, you could just by a Commbloc 7.62X25 pistol….

  3. The .327, as it’s currently marketed, fails the cost/benefit analysis for almost everybody. The risk and expense of using a new cartridge that may be abandoned by manufacturers in half a decade are real costs for anybody on a limited firearms budget, and for most they simply aren’t paid back by merely getting one more round in the cylinder.

    If somebody would make a five-shot .327 pocket revolver smaller than a J-frame Smith, then the cartridge would have a chance. Since no manufacturer is willing to gamble on the expense of tooling up for an entirely fresh handgun design, no customer base will be willing to gamble on the cartridge, and the .327 is going to go the way of the .32 H&R Mag.

  4. Americans just LOVE the phrases “new and improved” and “latest and greatest”.

    I also suggest that, with all the gun writers out there, some feel to distinguish themselves from the pack either by championing “the latest and greatest” or else attempting to explain why something that’s worked for decades isn’t any good.

  5. The .300 Whisper is not a great fit for the AR15 but the 300 Blackout is?

    That should make a great topic for debate.

  6. I have a pistol in 7mm BR. That means I am pretty sure that I need to reload for it. Thank goodness it is a single shot bolt action, or I would be spending all my days at the bench.

  7. The problem with most newer cartridges is that they are designed to fill a relatively small niche, or they are marketed in a small niche, despite having potential for arms flexibility.

    The .327 Federal is a case of too-small marketing. If Marlin or one of the other lever-gun makers would chamber a lever-gun in it, it would take off. When the cartridge was announced, that was expected, but hasn’t happened.

    The constant dribble of new cartridge offerings for the Stoner platform (AR) is the case of niche marketing, and niche marketing will never work unless the niche is immortalized by making it into a match caliber or some other such mechanism. The reason the AR has become “every-man’s rifle” is simply the vast number of ex-military out there now who carried it on duty, and who see the somewhat-limited cartridge as suitable enough for a carbine. All these new offerings for the AR make it into en even more limited-utility rifle. If the S.H.T.F. you will be glad to have either an AR in the original caliber or an AK in it’s original caliber. You will not be glad to have those weapons in other calibers.

    There’s something to be said for standardization. Wildcatting is always a possibility, but if you fall for a wildcat gun, you have no one but yourself to blame when you either can’t find ammo or have to pay through the nose for it.

  8. While many of the newer cartridges offer advantages, economics will kill most of them. When the economy is going gangbusters many shooters are willing to take a chance on “something different” even if the ammo cost is prohibitive. The reverse is true when the economy is poor. Personally I think that .327 is the only one of these latest cartridges with a hope of suceeding, and that is a long shot. It’s hope stems from CCW holders who want a revolver with more power and capacity than a .38 and less recoil than a .357.

  9. The main determination of a new cartridge’s success is how quickly the major manufacturers “legitimize” it by mass production. The new .30-caliber cartridges for the AR’s are still in the expensive “custom ammo” stage and won’t become popular until the big ammo companies get on board and make less-expensive ammo for the public. The same thing happened with the .327Federal….it has enough guns made for it, but only Federal/CCI makes ammo in that caliber. This is what has kept it languishing in the market.

    I really want to see the .458SOCOM, .300AAC, and .327Fed succeed…..

  10. I bought into the .32 H&R Magnum – While it is EXCELLENT, it is hard to find and super expensive these days. Hell, even the 32 S&W long that I can use as a surrogate is hard to find and right around the same price. I like the pistol but brass and bullets are more expensive than buying the overpriced factory stuff.

    Stay away from oddball calibers… I stick with my 5.56, .45, 44Mag, 9mm and .22

Your email address will not be published. Required fields are marked *

Time limit exceeded. Please click the reload button and complete the captcha once again.

Your discussions, feedback and comments are welcome here as long as they are relevant and insightful. Please be respectful of others. We reserve the right to edit as appropriate, delete profane, harassing, abusive and spam comments or posts, and block repeat offenders. All comments are held for moderation and will appear after approval.