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guitar-nut
06-12-2012, 11:42 PM
Sorry if this is one of those "beat to death" topics, but I was wondering if anyone here has experience with both Nitrided and Chrome Lined barrels and which you prefer?

From what I've read they're about equal as far as corrosion resistance, but one of my main concerns is heat from rapid firing.

MrPlink
06-13-2012, 12:16 AM
Hammer vs screwdriver

scglock
06-13-2012, 5:32 AM
not much of a difference tbh..

Mail Clerk
06-13-2012, 6:20 AM
Sorry if this is one of those "beat to death" topics, but I was wondering if anyone here has experience with both Nitrided and Chrome Lined barrels and which you prefer?

From what I've read they're about equal as far as corrosion resistance, but one of my main concerns is heat from rapid firing.

I've only tried chrome myself as there very common. They clean up fast and is very corrosion resistant. Nitride is a new comer to the block.

Mail Clerk

Richard Erichsen
06-13-2012, 7:12 AM
Sorry if this is one of those "beat to death" topics, but I was wondering if anyone here has experience with both Nitrided and Chrome Lined barrels and which you prefer?

From what I've read they're about equal as far as corrosion resistance, but one of my main concerns is heat from rapid firing.

Either works just fine and serves to protect the chamber and bore from chemical, thermal and mechanical attack. Both will be easier to clean than a plain untreated/unplated barrel surface. However, all things being equal the nitrocarburized barrel will be slightly more accurate mechanically unless precise and costly post-processing steps are taken on the chrome-lined barrel to re-establish bore dimensions that the deposition of chrome lining will slightly alter with variations throughout the bore and chamber.

The most common nitrocarburizing process used on barrels right now is molten salt-bath nitrocarburizing under the tradenames Isonite and Melonite, with the process types usually QPQ (for chrome-moly steel) or QP (for stainless steel). Q is for Quench, the actual process of submerging the barrel in molten nitrogen and carbon bearing salts and P which is for Polish, the mechanical polishing of bore and chamber surfaces after the first Quench operation. The outside of the barrel is treated during this process (more or less impossible to avoid) and leaves a lamp black, very hard surface that can be either left as is, media blasted prior to treatment to knock some of the shine off that can be present after processing (semi-gloss black) or blasted off and parkerized, blued, or painted.

Nitrocarburizing isn't new - it's at least 75 years old. European barrel makers started using it in the late 1960s after looking for a way to replace the costly and often finicky chrome plating process. It was already being used in marine, engine manufacturing and hydraulic applications. Now, most of the big European makers use a nitrocarburizing process instead of chrome plating. The IMI Galil in .308 I owned back in the late 80s had a nitrided barrel, something that I knew little about at the time and falsely assumed was just a cost cutting measure.

This process is only "new" to US barrel makers, not new to the world. Hydraulic equipment and engine parts have in many cases had nitrocarburized surfaces for 40+ years as an alternative to hard chrome, an application more common here than gun barrels. Unlike chrome lining, you don't have to buy your barrel already nitrided. You can have an existing barrel that has proven to be a good shooter preserved by nitrocarburizing it, or buy a less costly plain barrel and have it nitrocarburized. Contact Roccobro for details, we have a group buy opportunity to get whatever barrel you wanted treated and returned in a few weeks for a reasonable price.

R

kendog4570
06-13-2012, 7:24 AM
...... Nitride is a new comer to the block.....



Not hardly. It rears its head about once every ten years under different bling-bling names as the best thing that has happened to barrels since rifling. Anyone here remember Black Star barrels?? They went over like a lead balloon. Ten years before that Gale McMillan experimented with different processes that were similar. Very interesting report on his findings.

Nitriding is good for crankshafts. It probably has some benefit to various gun parts. Very questionable whether it is any good in a bore of a rifle. It sucks for the guy doing any work on it after it has been done.

6mmintl
06-13-2012, 7:35 AM
In my 25 years of highpower/shilouette shooting I know of only one person that uses a nitrided barrel on a 1x7.7" twist .223 barrel for long range shooting and quite sucessfully but that probably has to do with buying a premium barrel blank first.

The downside is you cannot sucessfully "set back/Recut the chamber" unless you have a carbide reamer and then you would most likely chip or shatter it recutting the chamber.

Richard Erichsen
06-13-2012, 5:24 PM
In my 25 years of highpower/shilouette shooting I know of only one person that uses a nitrided barrel on a 1x7.7" twist .223 barrel for long range shooting and quite sucessfully but that probably has to do with buying a premium barrel blank first.

The downside is you cannot sucessfully "set back/Recut the chamber" unless you have a carbide reamer and then you would most likely chip or shatter it recutting the chamber.

You'd have a mess on your hands with a chrome plated bore and chamber too, though on target barrels, that's virtually never the case. Since the process dramatically reduces erosion, the goal would be to extend barrel life as an alternative to recutting the chamber and crown.

R

Richard Erichsen
06-13-2012, 5:34 PM
Not hardly. It rears its head about once every ten years under different bling-bling names as the best thing that has happened to barrels since rifling. Anyone here remember Black Star barrels?? They went over like a lead balloon. Ten years before that Gale McMillan experimented with different processes that were similar. Very interesting report on his findings.

Nitriding is good for crankshafts. It probably has some benefit to various gun parts. Very questionable whether it is any good in a bore of a rifle. It sucks for the guy doing any work on it after it has been done.

You're right, the barrel had better be "finished" by the time you have it nitrided, or you are going to have a heck of a time adding that handguard notch, or gas block pin after the fact. In chrome lined barrels the area that needs to remain untouched is limited to the plating transition area of the muzzle/crown, bore and the transition area from the chamber to the breech face. The exterior of the barrel remains soft and easily machined.

Barrel life is as long as a chrome lined barrel with all of the same advantages of the chrome lining in the chamber and bore. Nitrocarburizing adds some protection to the crown and gas ports (if applicable) which are not typically plated. Gas erosion in the gas port or in the periphery of the muzzle crown are much lower in the nitrocarburized barrel as a result.

If you change your mind about how long you want your barrel to be or fancy a different muzzle crown, a shorter gas system or what have you, a nitrided barrel will pretty well beg the question - why not just buy a NEW barrel and spare the trouble modifying one? Given that gunsmithing charges can exceed the cost of typical sporting barrels, that may actually be the better approach and leave the current nitrocaburized barrel alone (though this can result in building a new rifle!).

R

Jpach
06-13-2012, 6:01 PM
Apparently the nitriding processes back say 50 years ago were just "alright" but now they seem to kick *** and modern nitrided barrels allegedly will last longer than a CL barrel, and have the potential to be more precise than a CL barrel.

kendog4570
06-13-2012, 6:32 PM
You'd have a mess on your hands with a chrome plated bore and chamber too, though on target barrels, that's virtually never the case. Since the process dramatically reduces erosion, the goal would be to extend barrel life as an alternative to recutting the chamber and crown.

R

Have seen many, MANY GI chrome bores, both M14 and M16, erode drastically at the throat long before the average match grade barrel in the same type gun takes a dump. When the chrome starts peeling, the barrel is done for anything other than just blasting at tin cans and hearing the gun go off. Hopefully nitriding will last longer.
Has anyone nitrided a match grade service rifle barrel and compared it to a non-nitrided one?

phish
06-13-2012, 7:59 PM
Sorry if this is one of those "beat to death" topics,



no mention of Colt, zombies, shtf, sniper, hicap mags, slidefire stock or 1st AR, so you're good ;)