do the shell casings look odd in any way? maybe u got some hot loads and its to much pressure? i dunno, just a thought....im still fairly new to the AR world myself.
I am wondering the same thing. The first round that was stuck looked like the case had swollen. I guess I'll try some different ammo and see if it makes a difference. I meant to last night, and got out there and realized I only had a batch of the same stuff.
you may have a non-chrome lined barrel that has lite rust in the chamber.
get a "chamber brush" and spin it with some oil on a hand drill lightly.
the casings expand and hang up on the rust.
most barrels will be marked with caliber between front sight and flash hider.
does it say anything there?
If it is a RRA upper the barrel info will be under the handquards. Take the handguatds off and the info should be stamped back towards the chamber end of the barrel. I beleive on the topside but you may have to look a little. To get the code meanings there are several websites that have it. The "other" sight that deals with this type of firearm is a good source for decoding. As for shaw barrels...not much info at their sight.