Gunblast article
 

He said the 7.62x39 is a rimmed cartridge(?). I'm no firearms expert, but.....

Couldn't have had said it better yourself! :)

Where did he say that? the article says the 7.62x39 is a tapered case, which it is.

Well damn. You're absolutely correct....I don't know where I thought I saw that. I guess I'll try to blame it on a quick glance at 5:45am with only 4 hours sleep and no coffee yet. At any rate I'm glad I was mistaken, I've always put a lot of stock in his reviews.

My apologies.

capable of subsonic sound-suppressed fire or full-power supersonic fire with ballistics comparable to the 7.62x39mm Russian cartridge

Not really unless comparable is usually 400-550 fps faster than the 30blk,with alot less pressure. The only real advantage is when you dont use a .308 bore and the mags which c-products or whoever they are now pretty much fixed.

300 AAC BLACKOUT, with Remington factory 125 grain Match ammo, is 16.7% MORE energy than Lapua 7.62x39mm ammo - when measured at 300 meters. I picked Lapua for the comparison because it is the only ammo with accurate BC and velocity data - and also happens to chronograph as the hottest AK ammo I have found.

It is impossible to fix. The AR magwell is straight. You can curve the mag all you want below the magwell, but you can never make the round go through the straight section properly. The mags were claimed to be fixed years ago also.

Not cheap, but it works. Just a thought.

http://www.mgi-military.com/index.php?id=27&sub_id=22

I have a Special Weapons lower which accepts AK mags. It solved the ability to take AK mags, but raised other issues:

1. You have to mill the bottom of the carrier to let the mag feed lips clear.

2. Hard primers - require an extra power hammer spring. But that is ok with a dedicated lower.

3. Still I broke bolts every few hundred rounds.