If I buy a upper assembly with the barrell and it doesn't come with a bolt or carrier, do I have to have it headspaced or does that affect the bolt\carrierassembly?  when do I need to have headspace checked, only when buying a barrell and upper seperate, I don't understand this very well yet.

suppose to check it on everything.






used especially

If it's from a reputable manufacturer..............you SHOULDN'T need to........................unless you don't trust them.

On ARs every thing is supposed to be "drop in", not like AKs, or other weapons where each part was hand fitted to a certain weapon. That's why the AR doesn't have a serial # engraved on each part, 'cause it doesn't matter.


I was just thinking to myself today, "I wonder if I should head space that new (used) M16A1 upper from CDNN?", then I thought "if it hasn't blown up yet, it probbably won't now!!!".