More food for thought: 300 whisper Vs. 7.62x25 subsonic

[brass shower]

It seems they have about the same case capacity and similar dimensions, with the whisper having slightly more case capacity. If you want it for subsonic only applications, why not load the 7.62x25 with heavy projectiles and use the subsonic whisper loads? Only snag I can see is bore diameter, since there's a lack of very heavy .311 bullets. This would be easily corrected by chambering the 7.62x25 in a .308" barrel though. Has this been done?

 

[The Drew]

I don't think it has been done... but I see the 7,62x25 round as being under utilized...

I think there is some great potential for this round... if only it were chambered in more firearms...

 

[Fumbler]

The problem is twist rates will not match up. Unless you plan on having a custom barrel made, 7.62x25 guns wont stabilize the same heavy bullets that the 300 whisper will.

 

[brass shower]

I thought about twist rate as well. But since chambering a .308" barrel for 7.62x25 will necesitate a custom barrel anyway, it should be a simple matter to chamber it in a barrel with the 1 in 8" twist required for 220-240 grain bullets.

 

[Fumbler]

Are you gonna have one made?

That'd be pretty neat. You've gotta post about it if you do.

 

[natedog]

What's the maximum bullet weight for 7.62x25mm, like 90gr. ? 300 Whisper can be loaded up into the 200gr. weight. If you're going to have a bullet speed limit set at 1,000ish FPS, you might as well make that bullet as heavy as possible.

Still, a 7.62x25mm AR-15 would be kinda neat, in a weird way. Especially if it took PPSH drums...

 

[Okiecruffler]

If it were a custom project, such as a Contender, I don't see any reason why you couldn't use a .308 chamber and load the 7.62X25 with those big slow 200gr bullets. I have a dummy round I made with a seated 150gr. Not sure what you would be gaining tho'. Easy enough to make Whisper brass from .223, 7.62X25 is abit more difficult to find. I have given some thought to doing kinda the same thing with the 32 mag, making a straight wall Whisper, or even necking down 357 mag brass to make a rimed whisper. These are the thoughts that make rainy days bareable.

 

[KriegHund]

Be nice if there were more 7.65x25mm guns in general. (For civilian use)

A Semi auto PPsh-41 or the like would be grand.

 

[only1asterisk]

The heavy bullet 7.62x25 has already been done if you believe J.D. Jones.

One would need a fast twist barrel, but other than that 180-200 grain bullets at 1000fps should be easy. I'd order 7.62x25 brass from starline.

David

 

[Harve Curry]

RPM of Tucson Arizona was building their design S.S. pistol for SF a while back. Used a 32H&R magnum case & 200gr .308"dia bullets.

 

[brass shower]

I'd love to get one made up but I dont have the time and funds for custom projects at the moment. I do have the time for thinking about such endeavors though. My reasoning for using the 7.62x25 case is that it's already similar enough to the .223 and 300 whisper so it should function in an AR-15 or other .223 based platform with minimal modification. It's also cheaper than .221 brass (11 cents a piece in bulk vs 18 cents) and wouldnt require any time consuming forming or annealing (time is money!).

 

[Okiecruffler]

But what could be better

Than case forming and annealing. Bending metal to your will under the torture of fire. Makes me grow chest hair just thinking about it.

 

[brass shower]

'Scuse me while I look at some midget porn to burn that image out of my head

So I found a piece of Tokarev brass and seated a 155 gr bullet on it to make a dummy round. It's ever so slightly larger than the .223 on the case head though, enough to prohibit it from fitting on my AR-15 bolt face which is disappointing. The .223 bolt would need to be opened up somewhat to accomodate the larger head diameter.

However it's the same diameter (give or take a thousanth of an inch) as a 9mm case head. And I got to thinking, why not use the bolt from an existing 9mm AR-15 upper conversion kit. Sure there are no locking lugs and it's blowback operated, but this won't be a high power round. 240 gr @ 1000 fps is the same power level as 45acp. The items necesary to convert an AR-15 would be a 9mm conversion with a 7.62x25 barrel installed (throated for the longer heavy bullets), and a heavy (8-10 oz) buffer to slow down the blowback operation. The same magazines should be usable.

The more I think about this the more I really want to try it. I'd like to develop loads on a bolt action however for safety's sake. Anyone know of a barrel manufacturer that can make a test barrel for cheap?