HBN coatings

[kelbro]

I have been coating bullets for a couple of years. It does seem to keep the barrel a little cooler on long strings and cleaning is a snap.

The write-ups all say that it will not impact into a polished stainless bore so it will not be as effective as if it were used in a CM barrel.

Is it a waste of time to swab the barrel with the slurry if you have a nice polished stainless barrel? Anybody borescoped one to see?

My hopes in using it was to get the temp carrying capabilities of a full bull barrel with a varmint profile and to prolong the life of the barrel. Is it really worth it on SS barrels?

 

[Scott Harris]

There is plenty of HbN in the bore after shooting a few coated bullets. Coating it ahead of time will get it done a bit faster, but seems like an awful lot of tedious work. Is your first shot super-critical? If you get foulers, seems like a non-issue. Another way to address it, is to document where your first shot impacts relative to your zero after the barrel is fouled.

 

[daj]

Kelbro,
I started using hBN in an effort to squeeze a bit more life out of my badly fire-cracked SS .308 barrel. While its competition days were over, I wanted to chop it down and use it for hunting. hBN took it from a 5 shot fouler that ripped off chunks of copper and couldn't hold moa, to a 20+ shot clean shooter good for sub moa. Not target grade but good enough for my hunting needs.
When I last scrubbed the bore back to bare metal, the bore scope revealed some copper but no large chunks in the fire-cracking as used to be the case. Despite pre-conditioning the bore with alcohol/hBN slurry some copper was being laid down in the first shots before the hBN built up.

I'm using the same technique on a new SS 6.5 barrel and still getting a little copper showing up under the hBN. However CCB shots are on velocity and in group.

 

[kelbro]

The source of the "news" that it doesn't help is somewhere on this site. What he was referring to was electropolished stainless barrels. There may be other vendors but Black Star is the only one I know of. The typical benchrest barrel you get from Krieger, Brux, Bartlein, etc. is no where near that smooth. The lap marks are clearly visible with my borescope and it's only 20X. I've been told but can't confirm that the major barrel manufacturers only go down to 320 grit.

Ahhh... that helps. And makes sense. I figured it was doing some good as cleaning is a snap. The barrels that I use it on have never coppered anyway but the carbon wipes out easily.

First shot has always been within an inch of the subsequent group and that's without swabbing the bore with the slurry. I'm going to try the slurry and see if that makes any difference.

I do have an older barrel that I may see if the HBN coating helps.

 

[Nomad47]

I have followed this http://theswissriflesdotcommessageboard.yuku.com/topic/9031/hBN-again-and-this-time-I-ll-leave-it#.US7daTeJDFl for three of my barrels. I used the slurry on one of my 6XC barrels before the first shot was fired down the barrel and the barrel has NEVER seen any chemicals - only dry patches.

 

[kelbro]

I have followed this http://theswissriflesdotcommessageboard.yuku.com/topic/9031/hBN-again-and-this-time-I-ll-leave-it#.US7daTeJDFl for three of my barrels. I used the slurry on one of my 6XC barrels before the first shot was fired down the barrel and the barrel has NEVER seen any chemicals - only dry patches.

That's close to what I'm doing with this new 6BR barrel. Fired my 10 'break-in' rounds nekkid and have only run HBN'd bullets through it since then. Made up a batch of the slurry to use before each batch but I'm not sure that it's really necessary since the bullets have a good coat.