.223/5.56 Marked Lowers...?

[Iraqgunz]

I realize that, but in fact across the board the chambers are not 5.56. IMHO anyways and based off of what I have seen.

There is no liability because no one has taken them to task. Maybe some of our legal scholars here could chime in and provide some insight.

Then that leaves Bushmaster (and any other manufacturer who does the same) open for some serious liability.

I know Ned's reamer has pulled shavings from all sorts of manufacturers' chambers. I'm not going to debate that issue. But I believe that C1911's point was that the manufacturer is identifying the chamber as 5.56. Whether they actually QC the chamber to insure it meets those specs is another matter.

[Omega_556]

And you've done that to each of your AR's?

I've done it yes, to each of my AR carbines no.

However I never said you needed to do this. You specifically asked "Then exactly how do I determine what chamber I have on my AR" and that is how you would know.

I have Colt, LMT, and Noveske carbines and, knock on wood, I don't have any reliability problems; ie failure to extract or popped primers.

If I bought a carbine that had a problem, Cerrosafe is one tool I'd use to diagnose the problem(s). If the chamber was out of NATO spec I'd first contact the mfg to see if it was within "their" production spec and if not I'd return/exchange it, if it was within their spec I'd ream it and know not to purchase their products in the future.

Maybe it is the mechanical engineer in me but I prefer to know exactly what I'm dealing with dimensionally before I stick a reamer in there and remove material. If I was an agency armorer I'd probably just jump strait to the reamer, but I'm a hobbyist and an anal one at that...