Thinking about a stainless nitrided barrel, anybody have any real world experience?

[Hammer_Man]

I currently have two 18" precision style ARs in my stable, a MK12 mod 1, and a franken build with an F1 barrel. Overall I'm pretty happy with how they both turned out, however it makes no sense to have two precision style guns in the stable. My plan is to use the MK12 for slow paced precision time at the range, and turn my franken gun into my general purpose blaster. I'm not sure how high volume quicker paced shooting will affect the life of the current F1 barrel, as the bore is not chrome lined, or coated at all, but I'm sure it will eventually wear out. Initially I wanted to buy a 4150 CMV chrome lined barrel, because they are known to take abuse, and I find chrome lined barrels require less maintenance than stainless. However, I'm curious about the recent crop of stainless QPQ/Nitride coated barrels that have become available. In my mind they seem to offer the best of both worlds. For one, they are available in multiple profiles which I like, because I prefer a medium to heavy profile barrel over the standard govt. profile. (Most CMV chrome barrels only come in govt. profile) Furthermore, if I can purchase something that offers the accuracy of a stainless barrel, and offers the longevity and ease of cleaning of a chrome lined barrel I would be a happy camper. Does anybody have any experience with stainless nitride coated barrels? How has the performance of the barrel held up with time/use? Does the nitride finish lend itself to easy clean ups after a day at the range?

Just as an aside the barrels I'm considering are: Faxon 18" heavy fluted, Criterion 18" stainless nitride, and Seekins 18" stainless nitride.

[Jsp10477]

I have a Lothar Walther that was melonited. I think it's getting close to 3k rounds. Most of those have been 69gr smk's. It took a little while to settle in initially but shoots really good. It cleans up pretty easy. It holds a little more copper than the ARP barrels we shoot do but it's still not much. We looked at it with a bore scope at around 2k rounds. It didn't have any of the cracking you usually see. It's been hot a couple of times but never used as a bullet hose. Over all, I'm pleased with it. I won't buy another one though. The ARP's shoot just as good, are ported smaller, 4150 cmv, 5/8x24 threaded muzzles, and cost about $100 less.

I've never owned a Faxon, Criterion, or Seekins barrel so I can't recommend them.

[BrigandTwoFour]

IMO, I don't see the point of nitriding a stainless barrel.

Cost savings aside (another reason nitriding has grown in popularity: it's cheaper than chrome lining), the benefit to nitriding was that it could be done to a barrel without negatively affecting its accuracy. To me, that is a real plus when done to a well-made CMV barrel that can be machined to a lighter profile.

While I see the potential benefit of doing the process to a stainless barrel for the purpose of increasing surface hardness and longevity, my understanding is that there is a very real risk of messing with the barrel's heat treatment/temper. Nitriding requires heating the barrel to around 750-1050°F. Coincidentally, that is also around the same temperatures used for tempering stainless steel barrels. I'm sure high quality barrel makers can account for that, but what are you really gaining over a tougher CMV barrel?

[Jsp10477]

Deleted

[Hammer_Man]

Thanks for the replies. The reason I'm mostly interested in a stainless barrel, is that I'm having a tough time finding a CMV barrel that is 18" with a rifle gas system in a medium, or heavy fluted profile. I will have to check out ARP barrels, I've never heard of them before.

[Jsp10477]

Daniel defense 18" s2w is rifle gassed. AR15Performance has 3 different 18" rifle gas options. There may be others. These are both 4150cmv. ARP barrels are button rifled and the DD is hammer forged.

Criterion claims as good as half moa accuracy from their chrome lined barrels. They have hbar and hybrid profile options.

[bp7178]

I'd speculate that everyone with a Larue rifle may be using a nitrided and/or melonite stainless barrel. IIRC, Noveske holds some type of patent regarding same. I can't say anything bad about mine. It seems on par with my old Bartlein/Compass Lake SPR barrel.

I haven't viewed for myself where Criterion claims 1/2 MOA out of their barrels. Double BS for a chrome lined barrel. Anyone who claims that for a AR15 barrel IMO is full of shit. Using worked up handloads that MAY be possible in extremely rare cases, but I still call bullshit unless I saw it in person. We're talking machine rested bull barrels and very precise reloading techniques.

I've shot hundreds of measured groups. IMO, a VERY accurate AR15 will hover just below 1 to 3/4 MOA when averaged over many groups over time. Using very high quality factory loads, this will be closer to or just above 1 MOA on average. I've shot extremely small groups, but they are a statistical rarity. Its very dishonest to take the smallest group you've ever shot and claim that to be the average accuracy of the complete shooter/rifle/ammo combo.

[Knife_Sniper]

I'd speculate that everyone with a Larue rifle may be using a nitrided and/or melonite stainless barrel. IIRC, Noveske holds some type of patent regarding same. I can't say anything bad about mine. It seems on par with my old Bartlein/Compass Lake SPR barrel.

I haven't viewed for myself where Criterion claims 1/2 MOA out of their barrels. Double BS for a chrome lined barrel. Anyone who claims that for a AR15 barrel IMO is full of shit. Using worked up handloads that MAY be possible in extremely rare cases, but I still call bullshit unless I saw it in person. We're talking machine rested bull barrels and very precise reloading techniques.

I've shot hundreds of measured groups. IMO, a VERY accurate AR15 will hover just below 1 to 3/4 MOA when averaged over many groups over time. Using very high quality factory loads, this will be closer to or just above 1 MOA on average. I've shot extremely small groups, but they are a statistical rarity. Its very dishonest to take the smallest group you've ever shot and claim that to be the average accuracy of the complete shooter/rifle/ammo combo.

How about 10 round groups from a button rifled chrome lined barrel?



Sample size of 2, both ten round groups.



The Criterion + Straight Jacket has shown tremendous accuracy potential and it is simply a button rifled barrel which is chrome lined. Those groups are from a 10x bushnell optic and my 52 Hornady ELD match loads over 25 of varget. I am sure if I had a machine rest this barrel could do better.

I was introduced to Teludyne Tech and the straight jacket by David Bailey who agreed to jacket my Criterion chrome lined barrel for T&E.

The mean radius is always smaller than the extreme spread, and is a valuable measurement. I have learned many things since first testing the Criterion and the barrel has evolved into something quite new. I would say never deal in absolutes. Chrome lined barrels are never that accurate right? This one is.

Or at least the chrome lining isnt destroying or diminishing the potential I would say.

I will agree with the satement that ammo is paramount.

[Cold/Bore]

How about 10 round groups from a button rifled chrome lined barrel?



Sample size of 2, both ten round groups.



The Criterion + Straight Jacket has shown tremendous accuracy potential and it is simply a button rifled barrel which is chrome lined. Those groups are from a 10x bushnell optic and my 52 Hornady ELD match loads over 25 of varget. I am sure if I had a machine rest this barrel could do better.

I was introduced to Teludyne Tech and the straight jacket by David Bailey who agreed to jacket my Criterion chrome lined barrel for T&E.

The mean radius is always smaller than the extreme spread, and is a valuable measurement. I have learned many things since first testing the Criterion and the barrel has evolved into something quite new. I would say never deal in absolutes. Chrome lined barrels are never that accurate right? This one is.

Or at least the chrome lining isnt destroying or diminishing the potential I would say.

I will agree with the satement that ammo is paramount.

You must be Lothean at thenewrifleman.com . I enjoy your articles. Thanks for sharing your experience.

[bp7178]

How about 10 round groups from a button rifled chrome lined barrel?

Sample size of 2, both ten round groups.

The Criterion + Straight Jacket has shown tremendous accuracy potential and it is simply a button rifled barrel which is chrome lined. Those groups are from a 10x bushnell optic and my 52 Hornady ELD match loads over 25 of varget. I am sure if I had a machine rest this barrel could do better.

I was introduced to Teludyne Tech and the straight jacket by David Bailey who agreed to jacket my Criterion chrome lined barrel for T&E.

The mean radius is always smaller than the extreme spread, and is a valuable measurement. I have learned many things since first testing the Criterion and the barrel has evolved into something quite new. I would say never deal in absolutes. Chrome lined barrels are never that accurate right? This one is.

Or at least the chrome lining isnt destroying or diminishing the potential I would say.

I will agree with the satement that ammo is paramount.

Kind of illustrates my point. Both are extremely accurate groups. But, neither is 1/2 MOA. I understand the difference between mean radius and extreme spread, but for purposes of this conversation no one was talking about mean radius. The accuracy of factory Criterion barrels was called into question due to a rather dubious claim about them being 1/2 MOA. Putting a jacket on a factory barrel...its no longer a factory barrel.