New cartridge idea.

This is idea I've had so I just want to get opinions.

We've got a lot of new cartridges designed around the AR-15 platform (6.8mm, .50 Beowulf). My thinking is along those lines.

Take a 5.56mm casing, cut it down 5/16ths of an inch. Load it with a 9mm bullet. The idea here is to recreate the .357 magnum for the AR. A revolver large auto pistol might use it as well. For added flexibility, have sabot rounds to fire .223, or .30 cal bullets.

9mm rifle barrels are not uncommon, the round would fit in AR magazines without modification.

So these questions come to mind:
1. would this work?
2. would anyone want this?
3. has this been done already?

Its hard to "neck up" a cartridge, you will have all kinds of feeding problems, among other issues

Necked down cartridges are common, such as a .357 sig.

The 9mm does approach .357 performance when pushed through a 16 barrel anyway, if you want better, they already make em in .357 sig, .40 S&W and 10mm.

What you're describing is similar to the .44 Auto-Mag Pistol cartridge. It's basically a .308 cartridge blown out straight and trimmed to length. In "To Ride, Shoot Stright, and Speak the Truth," Jeff Cooper proposed a light, semi-automatic carbine firing the .44 AMP as a PDW for soldiers who didn't need a full fledged rifle. Seems like you're talking about pretty much the same thing, just built around the .223 case rather than the .308.

If you take a .223 case and cut the neck off, and size it for a .30 caliber bullet, you have what is known as the 300 Whisper.

The only difference is that the top half has a .30 cal. barrel. THe maga and the bolt is the same...nothing needs to be done.

In the subsonic mode, its very quite when suppressed and has the energy of a .44 mag. In the supersonic mode is a bit more than the 7.62x39 and is popular as a deer killer.

Its easy to make. Just cut the case where the it necks down, then run through a sizing die and there you have it. It takes any .30 cal. bullet up to 220 grains.

For a more complete picture, look up JDJones on a net search.Hes the one that came up with the idea over 10 years ago.

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Originally Posted by HotGuns

If you take a .223 case and cut the neck off, and size it for a .30 caliber bullet, you have what is known as the 300 Whisper.

The only difference is that the top half has a .30 cal. barrel. THe maga and the bolt is the same...nothing needs to be done.

In the subsonic mode, its very quite when suppressed and has the energy of a .44 mag. In the supersonic mode is a bit more than the 7.62x39 and is popular as a deer killer.

Its easy to make. Just cut the case where the it necks down, then run through a sizing die and there you have it. It takes any .30 cal. bullet up to 220 grains.

For a more complete picture, look up JDJones on a net search.Hes the one that came up with the idea over 10 years ago.

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I have visited their shop and have shot two of their guns in 300 whisper. They are very nice. And very quiet. I plan on getting one hopefully by the end of the year.

Link: http://www.sskindustries.com/

I've never examined the magazine that comes with the 9mm AR-15 variants to see how long a case it will take, but I do know that what we call the 9mm here in the states - aka the 9mm Luger or 9mm Parabellum - has a metric designation of 9X19mm.

Some of the competition boys have been playing with 9X21 and 9X23 cases in an effort to make "major power" which you apparently can't do with the 9X19 case -at least not easily or safely.

Assuming a longer case would fit in the 9mm magazine, it should be fairly simple and cheap to rechamber the stock 9X19 barrel for the longer case.

This isn't the kind of project I would get involved with. I prefer to spend my money on training courses. "Screw the hardware. Upgrade your OPERATING system." I always say.

Still I know somebody who's been playing around with the 9X23, and here's his notes on it.

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My sub-caliber trainer (9x19mm Springfield Armory 1911A1 Loaded) has taken on a life of it's own. It's PRIMARY job is still low-cost training with inexpensive 9mm ball ammunition.

When the pistol is loaded with CorBon's 9mm Parabellum (9x19mm) DPX (115 grain solid copper hollow-point at 1275 fps), I do NOT feel underarmed for
carry/defensive purposes, BUT I just ordered a Nowlin drop-in barrel and bushing in 9x23mm as a special order from Brownell's. The 9x23mm drives a 125
grain .355" projectile at 1,450 fps (.357 Magnum ballistics).

The 9x23 case head is thick (like a rifle case) and operates at 40,000 psi while 9mm+P is 38,500 and .38 Super+P is 36,500 psi. For comparison, some
other common SAAMI pressure specs are as follows: .38 Spl is 17,000, .38 Spl+P is 20,000, .357 Magnum is 35,000, "regular" 9x19mm is 5,000, .45ACP is 21,000 and .45ACP+P is 23,000 psi.

Other than the additional 9x23 Nowlin-ramped barrel, my 9mm SA 1911A1 only needs .38 Super Mags (I'll use Wilson-Rogers) and a 20# recoil spring.
Otherwise, it is good to go. The 9x23 is said to be the BEST feeding round in the 1911 platform and is essentially a 11-shot .357 Magnum from a flat
semi-automatic pistol. It's too good a concept to ignore.

CorBon is going to make their DPX in 9x23 and I will soon get and test some of this ammunition in my SA 1911A1. My 9x23 carry ammunition until the DPX comes available is the CorBon 125 JHP at 1,450 fps. (W-W also makes two loads for the 9x23: a 125 JSP and a 125 Silvertip Hollow-point, both at 1,450 fps.)

"If you are going to shoot small bullets, shoot FAST small bullets."

A good link to 9x23 information:

http://www.burnscustom.com/9x23.html

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Blackeagle, exactly what I I'm going for.
As I suspected, there really are no new cartridges.