338 Whisper #2

[beesmyer]

I've found references to a 338 whisper #1 built from 7m case and #2 form .221 fireball case. But I have never found any barrels or reamers or any info on building a #2.

A #2 from .221 brass would be nice becasue then it would fit into a complete AR15 platform. The problem would be that there would be no shoulder to headspace from and headspacing would have to be done from the rim.

Is this a big enough problemn that no one does anything with it anymore? Since it's subsonic I don't think accuracy would be a great concern for being able to hit at great distances.

Is the #2 basically non existent now? What problems come from not having a shoulder? Is there anyone doing anything with this cartridge?

[cherokee]

http://www.sskindustries.com/ar10.htm

http://www.sskindustries.com/cartridges.htm

[beesmyer]

I already called and spoke with SSK. This is where part of my confusion is. They told me on the phone that they only chamber the 338 whisper in the AR10 (308) platform and it is based of the 7br case. They don't make a .338 whisper for the AR15 based off the .221 case. I asume that this has been dropped and the website is incorrect or out of date.

I called on the spectre cartridge as well and there 338 also is built from the 10mm case. THey won't build it from the .221 case either because of the lack of shoulder.

[cherokee]

As far as I know the 338 Whisper has never been built on an AR15 platform. The 300 Whisper was designed for the AR15 and it works very well. If you want a 338 Whisper in an AR then you will have to go with the AR10.

[AR15barrels]

You would not actually headspace the 338 #2 on the rim, but on the case mouth.
Headspacing rifle cases on the mouth just sucks.
The case is long enough that length variation from firing and sizing becomes an issue.
We don't see these problems with pistol catridges like 9mm or 45 or with the 30 carbine however because the cases are generally thicker walled and don't change lengths as much.
Also, many pistol extractors do in fact control headspace, even though they are not supposed to.

If you want a 338 in the AR-15 action, get one of Marty's 338 Spectres and call it done.
6.8 SPC magazines, 6.8 SPC bolt and 10mm mag cases are all easily obtainable.

Randall Rausch
www.ar15barrels.com (http://www.ar15barrels.com)

[Greywuuf]

I agree headspacing on the case mouth sux ( rifle or pistol) but.... if you wanted to do your own reamer, you could cut down .223 brass and have a substancial amount of "mouth" thickness to work with. This of course gives you a much thicker neck and the atendant problems, you would have to religiously trim your brass, and not inadvertantly 'bevel" them with your deburring tool. just consider it a AR in 45 acp (or 9mm) the nice thing is that straight cases lend themself to volume reloading on a progressive press.