I'm intrigued by the 300 BLK (300 ACC Blackout 7.62x35.) It approximates the performance of the 7.62x39 Russki and is much better suited to the AR platform. It can be loaded super or sub-sonic, and is a natural for a suppressor. In a short barreled/ suppressed firearm, it's well suited for home and urban defense. The donor-case is the ubiquitous 5.56x45 NATO/.223 Remington, cut down and necked up. Use of the 5.56 case allows the 300 to use the same bolt, magazines and somewhat the same chamber design.
And therein lies the problem.
|300 BLK in a 5.56 AR Pistol Barrel -- guns.com
The design of the 300 BLK allows it to fit into a 5.56 chamber. The Intrawebz holds this to be impossible, but there are too many reports and photographs of 300 BLK being (un)successfully fired in a 5.56 firearm. The shooters have not been noobs: most have been experienced and competent AR gunners. The .30 caliber bullet's ogive can neatly nestle into the 5.56 chamber's shoulders. The bolt closes and the trigger is pulled, and barrel, gun and shooter comense to having a very bad day. So far, there have been no reports of serious injuries. However, it's only time before "Someone gets kilt."
|300 BLK v 5.56 - onpointsupply.com
Who am I kidding? I'm much too much of an adherent to Murphy's Law to be completely comfortable with these solutions. This idiot needs idiot proofing. Perhaps, I'll just have to continue with my 6.8 SPC II experimentation.
Until someone comes out with a foolproof solution, I fear the 300 BLK might well be renamed the 300 Murphy, or alternately, the 300 BLK Irish.
It's best to keep in mind O'Toole's Observation on Murphy's Law: Murphy was an optimist.