JE, I was originally introduced to Melonite/Blk. Nitride treatment by a BR shooter that I was doing barrel work for. If it (melonite/blk. nitride) effected accuracy, BR shooters would reject it, entirely, many have their barrels treated. I have personal experience with having barrels treated. My 6.5 X 284 has 625rds down the Bartlien tube,,,,,, my 6mmRem A.I. has 510rds. Neither show any signs of wear,,,, not even alittle bit. I'd built a 6mmXC a couple of yrs. back. I had 52 rds 'down the tube' for break-in'. It was proving to be quite a shooter so I decided to have it treated. The throat was showing pretty good wear for only having 52rds across it, so I set it back two turns and re-set the headspace, fired two rds. to examine/measure the brass, cleaned it , and sent it off in a "batch' with 4 others. It was just as accurate as before. I had the same experience/results with a 6mm X 45mm. It had more rds than the 6XC down it. I set it back to fresh, fired 2 rds, claned it and shipped it. Just as accurate as before treatment. I know you have a bore scope. Wear starts from the very first rd. Some wear quicker than others. Some wear much quicker than you'd expect. The 6 X 45 was showing wear much quicker than I'd expect from that rd. I don't get to fire as many rds. from my own rifles as I used to. I always seem to be firing/working on someone elses. So, I've yet to fire one of my own, that's been treated, to "worn out". But, many of my customers fire many rds. , and the reports I get from them are nothing but positive. I bore scope many of them to see how much wear there is in the throat, which, as you know, is where the "wear" begins. I think some of the negitive that arises on the web comes from those who fail to completely clean the inside of the barrel before and/or after treatment. There's alot or residue left inside that has to be removed. The inside needs to be absolutely clean before sending for treatment There's no free lunch. I've spent an hour to an hour and a half cleaning a single barrel before re-installing it after treatment. I need to point out, also, that Melonite/Blk. Nitride is not a 'coating'. It is more akin to a heat treating process as it draws carbon toward the surface and infuses nitrogen into the surface of the material creating a "hard" layer, but leaving the toughness of the parent material. I've put a treated barrel under the Rockwell Tester at work, and it does increase the surface hardness (the one I checked showed 63C. took a lot of doing and a jack stand from the welding dept. to support the muzzle end for the shank to be under the anvil properly). The Melonite/Blk. Nitride process has been around for many yrs. and used on many different critically dimentioned parts, it's just been within the past 5-6 yrs. that its been used on rifle barrels. I my opinion, after observing 20 or so barrels, with none of them showing negative results, the process is well worth it. Understand, barrel makers won't endorse it as you are altering their material in a way that they have no control over. The 'blue' color, that the barrels come back with, is just a by product of the process. It can be polished off, if desired (with a barrel spinner and belt sander)
