Bolt Carrier markings

[Blitzking]

I've been working on a buddys AR and I notice his bolt carrier key wasn't staked at all. I also notice it had a SE inside a octagon stamped on the left side below the carrier key. Anyone know who made it?

[WpnsMan]

Sounds like an older Smith Ent. piece by the markings.

They use to come phosphated or chromed, with or without the carrier key. So, I wouldn't necessarily attribute the lack of staking the key to SE.