View Full Version : reaming chamber to adjust headspace

September 25, 2001, 11:25
I have a couple of questions. If the case is headspaced at the shoulder as with the .308 and the 7.62N, and the end of the barrel needs to be trimmed, let’s use an arbitrary number, .02 inches (because the end of the barrel bottomed out on the receiver), then wouldn’t the chamber need to be re-reamed by .02 inches to be properly headspaced? If not, wouldn’t the end of the case not be supported by .02 inches, thus causing a dangerous condition?

If this excessive headspace is caused by shortening the chamber, would reaming the chamber be the proper way of headspacing the chamber?

Thanks in advance!

September 25, 2001, 12:21
Headspace is set with a properly sized locking shoulder AFTER the barrel is fitted to the upper receiver. Trimming the barrel .020" (as in your example) would make no difference.

September 25, 2001, 14:50
First find out what the headspace would be. If from .256-.263, I'd use it as is. If below .256, I'd ream it.