Warning

 

Close
Confirm Action

Are you sure you wish to do this?

Cancel Confirm
AR15.COM
AR Sponsor
4/14/2013 10:45:39 AM EDT
I am using an Seekins upper that does not use the standard AR-15 barrel nut. I also don't have access to one at this time to measure myself.

I am looking for the dimension from the inside ridge that seats against the barrel extension (to hold the barrel in place) to the forward face of the nut.

See picture here if that is not clear:
http://i.imgur.com/yGGfVqF.jpg

What I am doing:

Adams Arms piston kit in a Seekins Precision IRMT-R upper. I need to turn the rod down a certain distance to get it to fit this extended upper. I'm going to take this measurement, and subtract it from this the distance from the IRMT-R upper forward face to the  forward face of the barrel extension. This measurement will be how far I have to turn down the piston drive rod.  This is because with the IRMT-R upper, the forward face of the receiver will be the spring seat, instead of the barrel nut.

Thank you in advance!
4/14/2013 12:39:17 PM EDT
[#1]
The M16 barrel nut drawing is out there somewhere as I have a copy somewhere.  I can't find it right now on my computer.

Try "M16 barrel nut blueprint" or "drawing" or look on those machine drawing websites for "M16."
4/14/2013 1:19:38 PM EDT
[#2]
Hey, Thanks!

I was able to find these two:

http://www.firearmfiles.com/files/AR15/M16_Barrel_Nut_Print%20-%20us%20army.pdf

http://www.firearmfiles.com/files/AR15/M16%20Barrel%20Nut%20by%20Teh%20Vice.zip
This one is an .IGS cad file, I don't have the program to open it.

From the Army file, it looks like 0.325" is the right dimension, can someone please confirm this?
AR Sponsor