Re: Advantage-Disadvantages of using moly coated bullets



On Sat, 24 Nov 2007 17:26:04 +0000 (UTC), 2000man@xxxxxxxxx wrote:

#has anybody recovered molly bullets ? how much copper is showing on
#the rifling marks?
#the thin coating is probably scrubbed off in 3 inches so the idea of
#it reducing throat erosion may be valid

If the bullet is truly plated there will still be moly in both the land and
grove impressions of the bullet when it's recovered. If, as often happens, the
bullet is merely 'coated' instead of plated, then you are exactly right, the
moly will only be on the first portion of the barrel.

Even a well plated moly bullet does not 100% eliminate copper fouling until the
barrel is seasoned. If the barrel is properly seasoned with moly there will
come a point where copper will never touch your barrel. The seasoning process
can be as elusive as a good moly plating. Similar to seasoning the barrel of a
muzzleloader, seasoning a barrel to shoot moly bullets requires a little time
(no one can say how long... each barrel is a law unto itself). Once done,
however, it's a wonderful thing to behold. And again, similar to muzzleloader
seasoning, it doesn't take much to ruin it! Once it's done, if your barrels are
like mine, you'll get a lot of shooting in before anything else needs to be
done.

First thing, how to tell if your home-plated bullet is really plated or if it's
just 'coated:' clean the bullet off with any clear solvent cleaner, such as
BrakeClean. If the moly comes off, it was just coated. Or simply wipe the
bullet off real good and drop in your pants pocket and carry it around for a
couple of days. If the bullet comes out all nice and shiney copper colored, it
was just coated. True plating is "really on there!"

I've had luck using a product called Coppermelt, although due to personal
differences in the way I think customer service should be handled between me and
the guy that made the stuff, I'll buy no more of it. Too bad, the stuff worked
great. The process I used involved shooting a moly plated round then passing a
patch damp with Coppermelt (CM) through the barrel. The CM doesn't do a thing
to the moly, it only removes the copper. After a few shots like this, the moly
is visible at the muzzle and the CM shows no copper fouling at all.

However, do be aware that the moly can build up to the point where it literally
starts to make the bore diameter smaller (and somewhat lumpy along the length of
the barrel) and it must be "cleaned down" (but not completely removed) to
prevent overpressure (if, that is, you're like me and don't down load your ammo.
If I'd of wanted 22-250 perfomance, I would have gotten one of them instead of
the Cheetah that I shoot). At any rate, when the CM is gone, I'll juse Butches
Bore Shine instead. I expect to get 2-300 round through a seasoned barrel
before it starts to build up... what happens in your barrel might be completely
different. There are no set numbers in this game, only hopes and expectations!

After shooting a while (no one can tell you how many... it's that law unto
itself thing again) you'll notice the plating building up by feel of a patch
going down the barrel (some spots may become more difficult to pull the patch
through) or by increases in pressure with known safe loads. It's pretty
obvious to me in my barrel, anyway. That's when it's time to run a patch with a
dab of JB Bore Cleaner though (many folks use a bronze or copper brush but I do
not care for them). I usually use just 10 strokes and then check again. I also
have a borescope, which is a huge help.

One last thing that has come to light via the benchresters over the years:
never shoot your rifle with bore completely dry, even with moly plated bullets.
There should be a very thin layer of something... Hoppe's #9, Shooters Choice,
Butches, regular oil (no teflon in the barrel, please!)... something of some
type in there to smooth the bullets passage. I suspect even WD-40 or similar is
ok if not too long a time passes before it's fired, since the WD type products
evaporate fairly quickly. This isn't some wives tale, it's been documented
time and time again by the custom barrel makers. This is especially true of
over-bore, high velocity calibers but applies to all rifles that shoot jacketed
bullets. The main thing it does is prevent checking and cracking of the bore
surface, especially in the throat area.

Now dumping in huge amounts of oil or solvent is not what I'm talking about.
Soaking your barrel down before shooting is *not* what is needed. This is
definitely a case where a little is just fine but any more is way too much.
Just a damp patch with your favorite 'stuff' on it is just fine. Large amounts
of that 'stuff' will likely throw your shot into the next county.... or worse.
Cheers,
jc


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