Barrels 101

[Airborne12b]

I know this is going to paint me as a noob, but I have to ask. I just built my first AR. This will not be my first time using the platform by any means, mind you. I have been isued probably 10-12 different AR variants over my time in the Army but none of these were NIB. The closest was the M4 that I was issued when I deployed to Iraq. As such I was never concerned with proper break in. For that matter I never remember in my time in the Army ever being told how to break in a new rifle. I am not sure if this is the best place to post this question but I figured that it being titles Barrels 101 that I would post it here. Thanks.

[Leethal]

Great stuff!

I know this is going to paint me as a noob, but I have to ask. I just built my first AR. This will not be my first time using the platform by any means, mind you. I have been isued probably 10-12 different AR variants over my time in the Army but none of these were NIB. The closest was the M4 that I was issued when I deployed to Iraq. As such I was never concerned with proper break in. For that matter I never remember in my time in the Army ever being told how to break in a new rifle. I am not sure if this is the best place to post this question but I figured that it being titles Barrels 101 that I would post it here. Thanks.

It's my understanding that with chrome-lined barrels, there's no "break-in" other than just shooting it.

You can find SS and unlined Chrome-Moly barrel break-in instructions on the web... there are several methods depending on the author. YMMV.

[Stik]

So from what I've read, Colt, LMT, CMT, BCM and the upper end (true mil-spec) manufacturers use 4150 and the more civilian recognized manufacturers like RRA, DPMS, Bushmaster, etc. use 4140? Just curious.

I figure most of the 1/9 twist barrels will be the 4140, but as I've stated in other posts, I'm a tech junkie and "just want to know". Also, alot of folks use "Wilson" (Wilson arms) heavy match barrels and E.R. Shaw "heavy match" barrels, I assume they are mostly 4140 when supplied to RRA, DPMS, Model 1, etc unless they are the 416 SS?????

Great post, very informative. Thanks for your time input into it.

[C4IGrant]

So from what I've read, Colt, LMT, CMT, BCM and the upper end (true mil-spec) manufacturers use 4150 and the more civilian recognized manufacturers like RRA, DPMS, Bushmaster, etc. use 4140? Just curious.

I figure most of the 1/9 twist barrels will be the 4140, but as I've stated in other posts, I'm a tech junkie and "just want to know". Also, alot of folks use "Wilson" (Wilson arms) heavy match barrels and E.R. Shaw "heavy match" barrels, I assume they are mostly 4140 when supplied to RRA, DPMS, Model 1, etc unless they are the 416 SS?????

Great post, very informative. Thanks for your time input into it.

BM uses 4150, just not the kind that the Military requires.



C4