JB, a lot of emotion on another forum about effect of moly coated bullets on barrels. I've heard and read so many different opinions on this that I'm unsure of what reliable data actually shows. Can you tell us whether molybdenum disulfide becomes irreversibly bonded to barrel steel? Is it removable with such agents as JB Bore Paste or other relatively common cleaning methods? I don't use moly coated bullets but have some of the old moly-coated FS 338s and wondered whether shooting them would alter my barrels irreversibly. Your knowledge would be appreciated. Thanks

I can tell you I run .338 FS's and conventional bullets with no ill effects. You can louse up load workup by combining the two.

I've never seen it bonded irreversibly to bullets....

Interested in JB's comments too, recall Moly Magic he used.

Moly wipes off bullets instantly with something... orange something IIRC.

I had a buddy shooting only moly in his 338, had to get it to bare metal to have it ultra bore coated.... the moly wasn't an issue but some stubborn copper at the muzzle took a few nights of scrubbing with JB....

I"ve shot moly in my competition rifles in 223 to the tune of probably 15 or so barrels shot out. Here is what I know of it. And its not scientific. It won't make a bad barrel better. It won't prolong barrel life. It does allow one to go to 500 plus rounds without cleaning. It does clean up easier than normal. It does allow more speed at the same pressure. That takes more powder of course... but it works out for what I was doing.

Right now if I had to start over again, I'd start bare bullets and ultra bore coat and see how that worked in the long run, and might still add moly on top of that.

For a hunting rifle I don't see the advantages. Just me.

Jeff

Your experiences mirror my own.. I use moly only in .17 Rem., 22-250, .243.. I can run over 100 rounds through the .17 before it needs a bore scrub..

But I do not use moly for any hunting round above the .243.. Just do not see any need...

I don't use moly anymore. Instead I use Ultra Bore Coat in those rifles where fouling can be a problem, especially high-volume varmint rifles. It justr makes more sense to me to coat the bore ONCE instead of every bullet you shoo through it.

At one point I investigated a lot of stuff about moly, and it was darn hard to find good research, believe me. One thing I did encounter was some data from a big ballistics lab. They found that moly tended tobuild up just in front of the chamber over about 50 rounds, then when it built up enough the next bullet blew the build-up out. They could see this in both pressure and accuracy.

I don't have pressure-test equipment, but did see this effect on accuracy in more than one rifle. It might be assumed this is why some moly shooters run a bore-brush up there periodically, to knock the moly back.

I have found that both JB Compound and Moly Magic get rid of moly in the bore, but it may take some work. This is from using a bore-scope to actually see what's happening, not just guessing.

Of course a lot of bore fouling also depends on the individual barrel, and the bullets and powder you're running.

It definitely makes sense to coat the bore once rather than developing different loads to fire coated and un-coated bullets in the same rifle - time better spent shooting the right load! Do you lap your fouler barrels before applying Ultra Bore Coat or does the material build up enough to fill the imperfections in the steel of the bore? Thanks, MD.

That's the entire point of UBC: It fills in the little machine marks and other imperfections. The big trick is that the bore has to be absolutely clean of all powder and metal fouling, and then degreased. Otherwise the UBC won't stick.

Thanks, will try it.

John

Very interesting on the moly.... I was a highpower shooter and did lots of group testing in 20 shot groups as a result for my own reasons.... I never was able to replicate the buildup, but funny enough a few other shooters had a similar build up in the throat, but were shooting bare bullets.... go figure, makes me think the moly build up issues could be more some type of chamber issue etc....

I"m all over UBC so far... so good. Have a BP rifle fired and reloaded now for a few weeks with tape on the muzzle, just cause I"m too lazy to fire and clean it and put awya from a hunt...

I"ve yet to try it in competition amount of rounds but it'll be in every barrel I use from now on.


PS there was a ceramic coating, Jtex???? years ago but it faded, have any info?
Jeff

Jeff, I don't know if it's the same stuff but OTIS is advertising a new "Nano Ceramic Bore Liner":

http://www.otisgun.com/cgistore/store.cgi?page=/new/fcatalog.html&setup=1&cart_id=

I don't know anything about it just saw an add for it in a magazine and looked up thier website. If it works anything near what some of their claims are it might be worth checking into.........................DJ