I’ve searched around but can’t seem to find the exact question having been asked/answered so here goes…
If you were looking to purchase a new barrel and money wasn’t a concern, which barrel type/finish combination would yield the highest accuracy, longest service life, and best performance all around after very high round counts? I know the best answer would be to just replace the barrel after __ number rounds but just humor me if you will…
Stock Stainless Barrel
Nitrided Stainless Barrel
Chrome Lined Carbon Steel CHF Barrel
Nitrided Carbon Steel CHF Barrel
this would be for an SBR… 10.3-11.5" roughly… either 5.56 or .300 Blackout… expecting high round counts (>40k) with mostly suppressed F/A fire
best of the best basically… I have seen a few guys on here that have Nitrided non-chrome-lined CHF barrels with awesome results…
Not sure if you used the Search function, but have seen multiple threads
discussing this topic. My take away analysis is: nitriding is potentially harmful for stainless barrels offering no benefits, and nitriding very helpful for non SS barrels, but jury is out as to longevity compared to chrome lining. Accuracy may well be better in a nitrided barrel compared to chrome lined one, all else being equal, but not likely to be better than a SS barrel of equal quality.
Believe Kyle Lamb’s VTAC II rifle has nitrided barrel, whereas VTAC I had a chromed bore & chamber, for what its worth.
Let the arrows fly !
I may have mised it in the previous threads but how is it potentially harmful to SS barrels?
On the OP’s question… I would go with a nitrided CHF barrel in your given scenario. That is, if you can find one HFed without the tolerances for the chrome lining.
Believe nitriding/meloniting/nitrocarbourizing reduces the corrosion resistance of SS. You can check the thread IG cited. Lots of info that should answer the OP’s questions.
I have a LWRCi upper, it has a CHF (ruger) barrel that is melonited. I have to say it is very accurate, In that regard I am very happy with it. Its accuracy is approaching that of my Noveske stainless steel barrel.
I have a LW Daniel Defense chf Barrel, it is noticeably less accurate than the LWRCi. I also have a KAC sr15 upper its CHF barrel (colt canada) is even a tad less accurate than the DD one.
Unfortunately (or maybe fortunately) I can not speak to the longevity of these barrels, I have thousands of rounds through each of them, but not enough to notice a difference.
If I had it to do again I would probably pick up a FN CHF barrel (psa, centurion or Noveske), they should last a very long time and are reported to be very accurate for a chrome lined barrel. I know the FN SPR A3G bolt action sniper rifle uses a chrome lined barrel and is guaranteed .5moa from the factory.
Actually the Melonite treated surface becomes the corrosion resistant property and is just as corrosion resistant as Melonite treated CMV.
Stainless is just that, stainless. Melonite treated barrels being CMV or stainless are more corrosion resistant than plain 416 SS.
Sweat or blood will make a ss barrel rust, it will not make a melonite treated barrel rust. I have an 8" chunk of ss barrel that was melonite treated about 3 years ago now, it has been laying in salt all of that time, it has not rusted yet. The part of the barrel that the melonite black was bead blasted off did rust overnight.
I can see having a true match grade ss barrel melonite treated to make it last longer but I see no benefit to using a production grade ss barrel and having it melonite treated when production CMV barrels are just as accurate.
Stainless steel requires exposure to oxygen to protect itself from corrosion as it is a self healing alloy. Without oxygen, it is susceptible to corrosion. (A good grade of stainless doesn’t rust. It corrodes. Only Iron and steel rust. Rust is iron oxide.) Chlorides are the enemy stainless steel. Chlorides not only cut off the oxygen, chlorides also cause stainless steel to corrode.
If stainless is melonited and that blocks off the oxygen, a small scratch could allow corrosive elements in that will spread under the finish as the stainless steel can no longer heal itself.
Likely, it’s not a big deal but why pay for the added cost of meloniting stainless steel if there is no real gain?
The only gain would be a barrel that may last twice as long.
Okay so the brown stuff on stainless barrels is corrosion, still shouldn’t be there. It would take one heck of a scratch to get through the melonite and transition layer.
I agree , why melonite stainless?
CMV barrels can be just as accurate as stainless and last longer it’s just that most gunsmiths don’t like to use it because stainless cuts like butter and they must take other steps when using CMV. Stainless wears quicker so it breaks in(smooths out) sooner. I have been using stainless barrels for 30 years but now that I have barrels being melonite treated monthly I have been using 4150 CMV. Like everything it’s a personal choice. My choice is to make my accurate barrel last as long as possible.