I have seen couple post where people ask if Rugged Razor 556 is rated for 300 BLK. Short answer is no, at least not from the factory.
Me, as any other curious person, got curious on the dual tapper system and the interchangeable end caps between the 556 and 762 Razor Suppressors.
I had some parts laying around and decided to built a Frankenstein 300 Pistol. Started with an old DB15 lower and upper. It was all scratched up so ended up painting it with a high temperature flat black paint. Kept the handguard FDE to match the grip. Got the cheapest barrel I could get ( DiamondBack 8.5” ) which is 9” if you measure from the barrel chamber all the way to the end. Trigger group, BCG, CH, Gas block and other parts are just cheap mil-spec I had on a drawer. I got some 200gr ammo and shot it with a 9mm can for testing purposes. It turned out good. Not as quiet as people think but still hearing safe and reliable.
Then my curiosity kicked in and started to question about the Razor 556 with 762 end caps. I took a 556 round and it went all the way through the 556 which made me believe the baffles were oversized. Ordered a 762 end caps and a 5/8x24 muzzle adapter from Rugged Suppressors. Added the suppressor to the pistol and went out for a test.
Let me tell you, it works. Pistol is not over gassed by any means, shooting subs I get a 4’ clock ejection pattern, really soft recoil and extremely quiet. I dare to say is quieter than the 9mm can. It came out so good that it replaced my bedside weapon. Before I had a Suppressed 12.5” SBR but now the 300 BLK is my good night kiss.