[ocabj]

I've reloaded 9mm and .45ACP for quite a while now, and am about to start loading rifle in .223 and .308. I've heard quite a few benchrest shooters prefer moly coated bullets over regular copper bullets to prevent barrel wear. Is this true or simply a misconception? Does moly coating in rifle bullets offer any significant benefit (accuracy, barrel wear, etc)?

[Steve Smith]

I think its safe to say that Highpower shooters shoot a lot more than BR guys every year, so maybe a study of their practices might be better. Unfortunately, they're as up in the air about it as anyone else. About half use it, the other half doesn't. The "for" camp says it reduces barrel wear. The "against" camp (where I am, btw) says that the actual bore wears very little in comparison to the throat, where accuracy is most easily affected anyway. Show me the moly coating that will prevent flame cutting at the throat.

[ocabj]

Hmmm... so moly coat is more of a personal preference? So are there disadvantages to using moly coated bullets (aside from the extra cost)?

[Steve Smith]

Just cost and time, both of which can be negligible if you buy bulk industrial moly and use a tumbler. No other disadvantage.

One more thing, it is messy as hell.

[bogie]

I've got a friend who really likes it - He's a gun writer, and also runs some matches, and instead of cleaning and loading between matches, he's either scoring targets, or schmoozing with folks. It'll let you basically shoot 60 or so shots without having to clean, and then cleaning is fairly simple, essentially just Kroil and JB abrasive. Works for him, and his barrels last pretty well.

Personally, I prefer to just use Butch's Bore Shine and naked bullets.

[Gewehr98]

From .223 to jacketed .45-70. On my really hot numbers, like .220 Swift, 6.5-06, and 6.5-300 Weatherby, the difference is well worth the extra effort, especially with respect to copper fouling and accuracy over time. Lots of powder in big cases will chew up a barrel throat in short order, regardless of moly or any other embedded lube. Cleanup is easier, and, for my purposes at least, accuracy is maintained over a longer portion of the barrel's life. I use Nalgene centrifuge cones, or small plastic aspirin bottles, to moly coat about 20 or so bullets in my vibratory tumbler. Then I use a dedicated corncob media sifter to separate the bullets from the moly powder. I save the moly powder and use it again and again, as long as I use clean bullets to begin with. Depending on how industrious I feel, I go the extra step and wax the bullets before seating them in their respective cases.

[bedlamite]

If you shoot bucketsfull of high velociry rounds in one sitting, the extra effort will be worth it. Moly doesn't foul the bore as quickly but you must clean it after every range session, as the sulfur left in the barrel can corrode it if left alone.

[Gewehr98]

Haven't had any of that alleged sulphur corrosion yet, with or without cleaning. And I'm in humid and hot Florida, no less. Molybdenum Disulphide takes a good bit of work to separate into it's component elements. Evidently, high-velocity, high-pressure rifle rounds ain't enough to do it...

[Clark]

I have ~50 center fire rifles, and only the two most accurate and often fired get to shoot moly:
1) 257 Roberts Ackley Imroved on VZ24 action Lothar Walthar barrel, 72 gr Berger MEF, 6.5x20x40 Leupold boosted to 13x40x40
2) .223 Rem on Ruger #1, 55 gr V max, 36X Burris

They get the bore burnished with Lyman moly bore paste at the beginning of the day, and get baking soda and water to flush out the acid [made by burning the paste ] at the end of the day.
They also get their handloads made with Forster benchrest dies.

Those two guns shot sub moa at 100 and 200m

But most of the other ~48 rifles are cheap beat up guns that have $20 used old Weaver K4 scopes and in calibers like 303 Brit, 7.62x54R, 7.92x57mm, .308, 30-06, etc. These guns get ammo assembled with Lee RGB dies and cheap bullets.

These other 48 non moly guns shoot 6 moa at 100m.