Home Forums Hunting & Shooting AR and Tactical Rifles So who has worked with the .300 Blackout (.300/.221) ??

I'll bite. What is the 7.62x40? Another name for the Remington 30 AR????

Great post and analogy!

No its Bill Wilson's answer to the 1-8 twisted and seemingly designed principally for subsonic use 300 blackout. The case holds more grains of powder, the barrel is 1-12 twisted or 1-11, its a 30 cal that fits into a standard magazine or slightly modified magazine that "goes faster" than the blackout and is designed to be a supersonic round, mostly hunting I would think. Mostly it uses the same bolt again, it uses the 5.56 parent case, and uses standard or slightly modified magazines. Foxbat unfortunately is a bit right though I hate to admit it, the blackout with a 1-8 twisted barrel is leaning towards 220 at subsonic speeds.

For that purpose, a pure hunting round, it probably is. I'm sure that you know this, but at the risk of being redundant I'll say that the ability to launch those long, heavy bullets at less than 1,050 fps as well as lighter ones at a reasonable speed in the same package is where the appeal of this cartridge lies. Not everyone is into suppressors. They are expensive, transporting them out of the county you've gotten approval to own them in can be problematic, they change your point of impact sometimes to a large degree, and they make your rifle unbelivably filthy with just a magazine or two. For me, however, they are the latest cool goodie I've been playing with and some of my projects reflect this.

Thanks - sounds almost like a 7mm TC/U, necked up to .30 Cal.

I would think that the 7.62x40 could run subsonic with 240's, but the 1:11 twist would not be good. Maybe someday I'll consider rechambering the Blackout barrel for the latter cartridge.

Anyhow, I have some load development planned

I asked Bill if you could fire the blackout ammo in the 7.62 x 40 in an email, got no response to the question so I suspect it will not work. IF cheap practice ammunition becomes available for the blackout, that is a factor, but as Remington has done twice before it could be here today and gone tomorrow as far as support is concerned. I think I will just get a 6.8SPC

Without looking at cartridge drawings I's suspect the headspace would be way short if you tried shooting the Blackout in a 7.62x40. Maybe even dangerously so, and I would not try it.

If a Blackout barrel with 1:8 twist proves unsatisfactory, though, it may be worthwhile to rechamber it for the longer round.

That's all speculation though, it would need study before attempting anything.

You're right, tex_n_cal...the Blackout is a 7.62x35. May or may not go off due to dropping down inside the longer chamber but why borrow trouble.