View Single Post
Old January 22, 2020, 10:31 AM   #256
Senior Member
Join Date: March 2, 2014
Posts: 7,447
How does one measure that critical bolt-chamber distance ?
It's pretty easy really. You can either use a no-go gage like ptg makes--or take a piece of sized brass and add thin spacers to the rim face until you you can't get the bolt to close without significant force--record what that measurement is. You should remove the ejector and extractor to get a precise measurement. As I've said, if that total space can conceivably exceed case support and still be within SAAMI max spec (which in the case of my Faxon AR set-up it could with starline brass)--toss of the dice whether your cartridge has necessary head support.

The thing is--the ptg no-go gage is set to not close at 1.714--so AR's and other auto-loaders might be compliant with SAAMI specs and still close on the 1.714 no-go gage. Not good.

I've already decided I'm going to use nothing but Hornady brass since it's the only brass that comes at a max length of 1.71. I wish I had known that before I ordered the 1,000 or so starline and winchester cases.
If you’re ever hiking in the woods and you get lost, just look up and find the brightest star in the sky and you’ll know which way space is.
I am NOT an expert--I do not have any formal experience or certification in firearms use or testing; use any information I post at your own risk!

Last edited by stagpanther; January 22, 2020 at 10:42 AM.
stagpanther is offline  
Page generated in 0.03300 seconds with 8 queries