I think School of the American Rifle started the 2 quarter spacing from the AR15 gas key and the receiver extension. I can not find an exact minimum spacing in the Army TM 9-1005-249-23&P Nov 2008. It makes too much sense for it not to be in there. If someone knows let me know and I will put it in the references.
I never have quarters in my pocket when I am working and if I do I will only have 2, what if I need it to fix a spacing issue? So I came up with this little gem.
It measures 2 quarters / 3.5mm thick and has a few stops to help hold it in place while you are cramming your BCG back trying to get the gauge.
Stops to help hold it:
Opening to let the BCG slide in:
Showing the gap:
Ref:
https://www.usmint.gov/learn/coin-and-medal-programs/coin-specifications
Hit us up with comments or questions
All Documents posted on this site are for informational use only. If you make ANY modifications to your Weapons based on this site, you do at your own risk! If done incorrectly, you can render you weapon unsafe and / or unusable.
More HERE: https://viking-armory.com/?page_id=723
