AR Barrel Bore Pin Guage

[markm]

What pin guage(s) is/are best for confirming an AR .223 barrel isn't under-bore?

I'm trying to isolate the reason a barrel is shooting high velocity and popping primers. I measured jump to lands, and that matches a known good (Colt) barrel. So I'm down to tight bore, or non-5.56 chamber.

Pin guages are cheap, so I'd like to eliminate the tight bore possibility before spending the money on a 5.56 Chamber reamer.

SHOULD at .223 pin guage pass through an AR 5.56 barrel??