Try PSA. I have bought from them before and their stuff is good.
Ammunition, Magazines, Rifle Parts, Bulk Ammo and Rifle Accessories - Palmetto State Armory
I can definitely see your logic in that but from what ive read if all parts are mil spec then there is no need to check the headspace. Can anyone verify this?
Im building my first AR and was wondering is it necessary to check the headspace before I put it together and shoot or is it not really an issue. I've heard yes to both but I wanted to see what y'all thought.