View Full Version : RRA NM Barrel VS. Standard SS barrel ? ?

09-28-2010, 9:10 PM
I just ordered a Standard A4 20" Stainless Steel Upper.
Will that barrel be the same barrel they use in the NM A4 Upper ?
Their desciption for the NM says Air gauged 1:8 Heavy NM.
Description for the one I ordered says Air gauged Stainless Steel 1:8
When I check their catalog for barrels only, They only offer one SS 20" Hbar
1:8 and it does not say it is NM

09-28-2010, 9:42 PM
call them in the am.

09-29-2010, 2:22 PM
Got ahold of RRA, and Yes they are the same barrel :)

09-29-2010, 8:31 PM
yep, same barrel indeed.

09-29-2010, 8:52 PM
What are the results of the air gaging? An air gage is merely a method of measuring bore dimension, or differential in any given bore. It replaced the renowned Star Gage of 1903 Springfield fame. A true "match-grade" barrel would be no more than .0001" difference in any given bore, with any tighness (max .0001") at the muzzle end.
The dimensions are more important than the measuring method, and price is usually a good indicator of the barrel quality.