Warning

 

Close
Confirm Action

Are you sure you wish to do this?

Cancel Confirm
AR15.COM
10/28/2008 9:37:31 PM EDT
For a 20" RRA standard (Heavy) barrel, would the unlined chromoly barrel offer any advantage over the 20" stainless barrel?  Would the CM be any more consistant as the barrel heats up or offer any possible advantages?  With money not a factor, any reason not to get the stainless?

BTW, what is the rate of fire and round count for match event strings in which the stainless barreled RRA NM rifle would typically complete?
10/29/2008 4:17:00 AM EDT
[#1]
I'll let someone else weigh in the CMP Match courses of fire.
Barrel to barrel, you have different materials and twist rates.  The moly barrel is a 1:9, while the stainless has a 1:8.  The faster twist of the stainless will stabilize heavier/longer bullets than the 1:9 would tend to, but also won't stabilize somewhat lighter bullets as the 1:9 might.  Stainless has somewhat better heat characteristics than moly as well.  
And, of course, a moly barrel is phosphated to a dull blackish color, whereas the stainless is goign to be silver (matte silver if bead blasted, but still silver).
Steve/RRA
10/29/2008 11:24:50 AM EDT
[#2]
Thanks Steve.  I just learned something.  My guess would have been that the stainless would have been more likely to change POI as the barrel heats up.

One more question - Are both barrels manufactured to the same level of precision?

Thanks again.
10/30/2008 4:26:27 AM EDT
[#3]
Actually the 20" stainless are all air gaged match barrels...while the moly are not air gaged.
Steve/RRA
11/1/2008 10:17:17 AM EDT
[#4]
Thanks I went ahead and spec'd stainless for my order.

For future reference, what are the tolerance limits on the air-gauging inspections?