So I'm loading up some match ammo for a new AR platform... .223. Take some headspace measurements from once fired brass from the new rifle. I start full length sizing the brass and bumping the shoulder .002" back. It's set up to be a precision rig so I figure .002" is just right while still keeping reliability up also. I measure a few pieces of f/L brass bumped back as mentioned then decide to chamber a few pieces of brass to check for extraction and chambering. I then measured the brass again and found the shoulders on all the brass had been pushed back an additional .007" which means its more .009" under the once fired brass.
My two cents: I chamber the brass by pushing them into the chamber by hand them allowing the bolt to slam forward just is it would when naturally chambering a round or during firing. I suppose the shoulder is being pushed back by the extractor pushing the brass onto the chamber just before the extractor claw jumps over the rims of the case.
Needless to say, I started thinking if i was wasting my time with trying to be precise with headspace on an AR platform. Am I missing something here or is this S.O.P. on an AR?
My two cents: I chamber the brass by pushing them into the chamber by hand them allowing the bolt to slam forward just is it would when naturally chambering a round or during firing. I suppose the shoulder is being pushed back by the extractor pushing the brass onto the chamber just before the extractor claw jumps over the rims of the case.
Needless to say, I started thinking if i was wasting my time with trying to be precise with headspace on an AR platform. Am I missing something here or is this S.O.P. on an AR?
