View Full Version : headspacing

June 26, 2007, 22:13
Newbie to FAL question here: I have read the FAQ regarding headspacing and have removed the extractor from my bolt and inserted a Forster GO guage. The bolt requires moderate effort to close on the guage. I read in the FAQ section about " two thumbs" worth of pressure, what is the correct amount of force or lack thereof for closing on this guage?

Mosin Guy
June 26, 2007, 22:19
Lots To Read in Here http://www.falfiles.com/forums/showthread.php?s=&threadid=119640

June 26, 2007, 22:27
"Two Thumbs" can mean about anything without prior experience (and it still means diff things to diff people.

If it closes with very light pressure (a hair more than none) on the GO, just install the LS that matches that pin for a HS of 1.631+ to 1.632. If using the "add one, subtract two" method you need to start with "two thumbs" or what I would describe as moderate-plus -- but why do the math?

June 26, 2007, 22:32
Thank you for the link!

ratas calientes
June 26, 2007, 22:36
I will assume that your chamber, bolt face, and gauge are clean. I also assume that you are using a pin gauge to judge the relative size of a locking shoulder. Then the bolt carrier should close with a few pounds of force on a GO gauge. Then, if you insert a NOGO gauge (Forster, which should be 0.004 inches longer) it should NOT close with 10's of pounds of force. Then select a locking shoulder that is 0.001 to 0.002 SMALLER that the pin gauge. After you install the locking shoulder, check again. It should close with no effort on the GO, and not on the NOGO.

Now, if I were doing one build, and I used the locking shoulder from the kit, if it still closed on the NOGO with some effort, I would keep it as is. It is still plenty safe to fire.

Let us know how it goes.

And welcome to the Files. http://chilirat.com/emoticons/chilirat.gif