Yet another AR question - check headspace?

[t0tln00b]

I picked up a PSA lower w/o the bcg and someone at work said I should check the headspace to make sure the bolt fits the barrel assembly? The interwebs has conflicting info on whether this is necessary - oh noes ur gonna die if you do/don't - but can anyone tell me if this is a real function check, or a way to sell more tools?

 

[BradMacc82]

It's a real check, and one that shouldn't be casually dismissed at times.

Excessive headspace can cause issues.

 

[-Z/28-]

Do you mean an upper?

In theory any name brand bcg should be in spec and work fine. But I am not a gunsmith.

 

[mopar92]

If brand new parts are being used it shouldn't be an issue. However it's your rifle and your face at risk.

 

[BradMacc82]

In theory, for brand new parts it shouldn't be an issue - on my last build, we didn't do a true headspace check, we just took it to the trap and let it rip. But a quick inspection of the spent casings told all that was needed.

With that said, you should be OK, but I'd check your spent casings for any obvious signs (when it's done of course) and proceed accordingly.

 

[t0tln00b]

As always - thanks for the quick replies! I watched the brownells video on checking headspace - so it is basically to check the bcg/bolt doesn't go too far forward or sit too far back? How would the spent casing show either or what am I looking for on the casing? I do try to google (and searches specifically for this site) for answers but direct questions are usually answered faster and more accurate than what I find....

 

[Half-cocked]

Just ask Will at Red Jacket to have a look at it.

 

[BradMacc82]

Blown out primers can be a sign of excessive headspace, along with case-head separation, IIRC. I'm not the best one to answer that question since some people here have forgotten more than I know about these types of things.

 

[mopar92]

http://www.mdshooters.com/showthread.php?t=80734
Specifically the link in the first post.

 

[Forest]

I picked up a PSA lower w/o the bcg and someone at work said I should check the headspace to make sure the bolt fits the barrel assembly? The interwebs has conflicting info on whether this is necessary - oh noes ur gonna die if you do/don't - but can anyone tell me if this is a real function check, or a way to sell more tools?

Is it needed? Not really. Is it nice to do? Sure.

Do I do it? Yep annually and every 1K rounds.

Use the USGI Field Gauge. The USGI version of the tool doesn't require you to disassemble the bolt (making it quick & easy to use) and is properly sized for a 5.56 chamber. Using commercial .223 field gagues can FAIL a perfectly good 5.56 due to differences in the tolorances.