Is this gonna work?

[1 LT MPC]

I have an old Colt HB AR 15 sporter II (circa 1988) with a 20 inch Hbar that has never been fired. I want to put a 16 inch Del-ton pencil barrel with an A2 upper on the Colt. Can I use the BCG from the Colt or will I get into headspace issues?
Any thoughts? (I understand about matching the front pivot pins).

 

[rcmodel]

In theory, all AR-15/M-16 bolts ever made will headspace properly with any barrel extension ever made.

I would try it, and I would expect it to work.

But I would check it with a 5.56 headspace guage too.

rc

 

[1 LT MPC]

Headspace guage

Any reliable way to test without the guage?

 

[briansmithwins]

Any reliable way to test without the guage?

Nope, that's why they make gages.

USGI FIELD gages run about $35. They can save you from blowing up a rifle and stuff.

BSW

 

[1 LT MPC]

Do I buy the GO gauge or the NO GO, or both? I really didn't want to spend 60 bucks on a set of guages. The USGI field guage is just one, correct? But I've read that their specs are different. Also, I have to remove firing pin and extractor from the bolt for guage use.

 

[Al Thompson]

How about sign a set out from your SA contact team at the FSB?

 

[1 LT MPC]

Negatory, unable, retired.

 

[rcmodel]

How about $16.99!
Here is what you need:


http://www.brownells.com/.aspx/pid=6646/Product/5_56mm___223__HEADSPACE_GAUGE

rc

 

[briansmithwins]

The FIELD gage is really the only one you need to check rifles that are in service. The USGI gage has the advantage that you don't need to pull the extractor, ejector, or anything else to check headspace, unlike the gage from Brownell's The USGI gages run about $40.

If you go over to ar15.com (hometown forums) you can probably find someone in your area that already has one and will get your rifle checked out for you. BSW

Here's how you would check it:

 

[1 LT MPC]

Thanks for all the input. After looking at prices and shipping, I just had Del-ton add a BCG that included test firing and headspace specs--cost about 65 bucks and gives me extra parts.