Titanium nitride (TiN) coating for barrel bores

B

bluechip

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TiN coatings are as hard as carbide, less than .0001 thick, extremely slippery, heat resistant and very good at resisting metals (lead, copper) sticking to their surface, so why haven't they made their appearance in the barrel bores of custom rifle shooters? This coating has been around for some time now and is proven in many fields including the cutting tool industry for both steels and carbides.
 
We use a lot of TiN coated tools at my Shop. Lathe insert tools, end mills, taps.

They do wear out.

Plus, these coatings are already on a extremely hard surface( high speed steel or carbide), with just about zero ductility.

I'm not sure how well it would stand up on a relative soft material subjected to the extreme heat and pressure as exhibited in the throat of a rifle barrel. Barrels do expand when hit with the sudden pressure spike, the TiN, which has zero ductility, might be compromised.

But the, the military has hard chrome ID's in some barrels.
 
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Since the 1980's we have been "hard-coating" our already hardened cutting tools. The primary coatings that have really worked and been proven practical have been TiN (Titanium Nitride-the gold one) and TiC-Titanium Carbide. Unfortunately, both require application methods not suitable for coating internal surfaces on materials such as the steels we use for rifle barrels.

The most efficient and effective coating method is CVD-Chemical Vapor Deposition, this method requires taking the material to be coated to over 2,200F. The second commonly used method is PVD-Physical Vapor Deposition (Sputtering), this can occur at temps as low as about 800F. For a PVD method to be used, our finished machined barrels would have to be coated then re heat treated.

There have been many other types of coatings that have been used in "gun barrel" bores but none. so far, have proven worthwhile in what marksmanship types have needed.

.
 
Melonite

I once had a barrel melonited. It shot fine after it was done. Do a search on here and you can find out about it.

Pete
 
I don't think coating a Benchrest barrel with anything is much more than a curiosity. Others may, and are free to, disagree.
 
A couple more thoughts

Other options would be to make the entire barrel from something like chromimum or silicone carbide. Or make ceramic barrels. Progress in any field is often made by going outside the normal methods of thinking. I simply don't have the financial means to do this sort of experimenting. Doing work like this would put the experimentation back into the EX class wouldn't it ? which has just become rail gun shooting.
Andy.
 
A while back a barrel maker, I think it was "black star", came out with a new stainless alloy that was supposed to be superior to 416. You don't hear about it anymore. To all
 
A while back a barrel maker, I think it was "black star", came out with a new stainless alloy that was supposed to be superior to 416. You don't hear about it anymore. To all

It wasn't really "new", just some grade of precipitating hardening stainless steel in the same Familly as 17-4 and 15-5 PH. BlackStar was using Lothar Walthar barrels with some proprietary electro polishing in the bore.

Great for an over bore hunting chambering where throat erosion might be of a concern. Not so much for a barrel dedicated to extreme accuracy.

Hear is a rather humorous story about them. Back in the Late '90's, when Glen Newick was still running matches at the American Shooting Center Complex in West Houston, the BlackaStar crew showed up with a big tent, an impressive display, and a young shooter who, (not kidding), was telling everybody how this wasn't even going to be a contest, so to speak.

Well, reality set in pretty quick, and I think the entire bunch packed up and left before the morning was up.

I remember Butch Lambert, Jerry Hensler, and a others getting a good laugh out of that.
 
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