Headspace needed new upper new bolt carrier

[WilliamAnderson]

Do I need to go to the gun shop and have my new bolt and new upper headspaced to each other, or can I just throw it in the gun and go shooting?

[Josh3239]

Headspacing is set at the barrel extention. I wouldn't and haven't in over 10 upper builds and never one problem. If your buying good parts I wouldn't bother. I once matched a new bolt with a barrelled upper from the late 60s and a gunsmith offered to check the headspace for free for me, no problem.

[wash]

You can use scotch tape on a live round to identify if you have a dangerously large headspace.

The specs on AR bolts are usually held quite tight so headspace problems are rare.

Tape is not as good or reliable as a No-Go gauge so make sure you know what you are doing.

If you don't know what you are doing and you have a problem, your barrel could blow up in your face so make sure you understand what you are doing.

[WilliamAnderson]

Sounds good to me!

[chead]

What causes headspacing issues?

[metalliman545]

Excessive wear. Screwing the barrel in too much or too little. Bolt face/head inconsistencies is what comes to mine