Will Moly cause leading

dg101win

dg101win

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To clarify this question--Will switching from Moly coated cast bullets to non-moly coated cast bullets cause leading if the moly coating in the bore is not cleaned out?
Up until this summer I was using cast bullets in my 44 Spl's and Mag's.

S47B,Lipseys 44Spl,50th Anniversary Flattop,and S&W 624. Leading was not a problem using 240-250 cast bullets with Unique. Also they all shot great.

A friend gave me some cast 240RN's that he moly coated,brand unknown. So I loaded them up and started shooting them and they shot pretty good. Then I switched back to NON MOLY coated bullets and got leading. After 20 rounds I get severe leading in the first 1-2 inches of the barrel. Also acuracy went south real fast. I got out the chore boy and the Lewis lead removal tool and cleaned out the lead. Followed this up with Kroil,CorrosionX and M-Pro7.

Went back to the range and the same thing happened. Much more of this and I can sell the strips of lead the chore boy cleans out.
My loads are only 6.8 of Unique in the specials and 8-10 of Unique in the mags.

I understand all about bullet dia.,bore dia.,hardness of alloy used and all that. These loads shot great before now the leading. So am I not getting the moly coating out? If that is the case what would the suggestions be for a bore cleaner to get the moly out?
 
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Moly is some very tenacious stuff. The only thing that I have read that works on removing it is JB Bore Paste. But look at the bright side, at least it's handguns and not long rifle barrels.:)
 
I'm not claiming to be an expert, this is just what I've read.

Once you go moly, you can't go back. It does give higher velocities if used on your bullets but once your barrel gets coated with it it actually acts as an abrasive with non moly bullets resulting in lousy accuracy, excessive fouling and...pretty much what you are finding.

I had bought a box of moly bullets before I'd heard this, but read it before loading them. I dumped them real fast and avoided them like the plague heeding the old wisdom of "if it ain't broke, don't fix it". All of which means that I don't have a clue what to use to try and clean your barrel out.
 
I have shot Moly bullets in my 1000 yard rifle and in my service rifle.

I have shot moly and non moly bullets on the same day with no problems.

Even though I use Moly I still clean my barrel and chamber after the days shoot.

I think most of the problems with moly happen when some shooters think they never have to clean their barrels once they start shooting moly...
 
Greetings
Are the non moly bullets of the correct diameter ?
If they are under cylinder throat diameter that could be the culprit.
 
Missionary said:
Greetings
Are the non moly bullets of the correct diameter ?
If they are under cylinder throat diameter that could be the culprit.
Click to expand...

The non-moly bullets shot great beforehand,minimal leading. I guess the moly coating left in the barrel is acting like an abrasive.
The bullets were free,the friend just didn't care for that weight in his rifle. He also gave me 200 or so Laser Cast 300grTC .431dia. WITHOUT Moly. I'll probably never use those.
Guess time to get some J-B Bore Paste.
 
I almost bought a box of 40 SW lead Molly coated bullets. They where on sale as the shop was going out of business. I bought all the regular lead ones for a steal.

I posted on another forum and asked a Master Gunsmith about the Molly who warned against them for the very reason you are posting. He is the one who recommended the bore paste.

I have a tube of it as it is great for once or twice a year cleaning, takes out anything and leaves the bore nice and clean.

Send me a PM with your address and I will send you a "blob" of it if you want to try it. You do not need the oil that comes with it, any oil will work.
 
OCD1 Thanks for the offer to send some.

But I went out this morning and found some J-B at the local shop. Time to break out the brushes and patches again.
Thanks to all for their suggestions.
 
Wonder if the moly built up in the rifiling to the point where the bullets can not engage it fully and are stripping as they pass through the barrel and not spinning up and that is causing your loss of accuracy. Moly is a lubricant not an abrasive. Either way that crap needs to come out of there.
 
Poeple that use it and don't clean will find that out. We has a BUTT HEAD at a high power match split the barrel because he didn't clean that junk out of it.
 
I don't have any experience with moly coated handgun bullets but shot benchrest rifle for several years. At one time, nearly everyone was using moly bullets in their 6mmPPC benchrest guns. Cleaning was typically done with J-B bore paste and a 50/50 mixture of Kroil's and Shooters Choice (or your favorite solvent). The benchrest shooters stopped using moly when it was found that the moly builds up in the leade of the rifling and can't be removed. I ruined the fine accuracy and required barrel replacement. Not sure how this applies to handgun shooting but I don't use moly anymore.

In rifle shooting, you would have to increase the powder charge to return to the same velocity achieved with non-moly bullets.
 
A little moly trivia.

A friend loaded his service rifle practice ammo on a progressive machine.

One time he loaded a few rounds with no powder.
When fireed in his match 223, naturally the rounds stuck in the barrel...

Later he had switched to moly coated bullets.

Again he loaded some rounds with no powder...

When fired, these bullets cleared the barrel...

As an experiment he loaded a few more on purpose with out powder. Again they all cleared the barrel...

Makes me think that moly does indeed reduce friction.

I do know my barrel is cooler when shooting moly bullets.

If I remember correctly Norma tested moly bullets in their 6.5x55 loads and barrel life was almost doubled.

My barrels copper and powder foul a lot less with moly bullets.

You can shoot many more rounds before accuracy starts to fade...

It makes it unnecessary to clean between relays, to maintain accuracy.

I just clean at the end of each days shooting.
 
Alot of pulp fiction, urban legend & plain old hear say going on in this thread.

The moly residue can easily be cleaned out of the bore with a metal polish called never dull.

Moly isn't abbrasive, it's the exact opposite, that's why people use it. It makes the bore slicker causing less friction & keeps the bore cleaner longer. The theory behind it is the bore gets coated from shooting the moly coated bullets. Because it coats the bore & makes it smoother the next shot down the tube will clean out the fouling from the prevous shot keeping the bore clean longer.

There's alot of products out there that take avantage of what moly can do. Engines, drillbits, bearings ect, less friction equals stays cooler & longer lasting parts.

I don't use moly coated bullets, I treat my bbl's & other gun parts with moly instead. The moly actually gets into the pores of the metal that creates a film that is extremely slippery. I can actually feel the moly starting to work as I treat a bbl with it. And you talk about beautiful smooth as silk triggers, just plain sweet.

If I work on something or get it broke in then I like to treat the finished product with moly. The moly makes the work even smoother & makes the metal parts last so much longer.

One of the more surprising thing that I treated was a 1911. After I got done I put a progressive spring that had a 24# max rating in it. Then I took it to the range & ran 5 10 round mags of ammo threw it as fast as I could pull the trigger. Afterwards I grabbed the bbl with my bare hand & it was cool to the touch.

I've treated many bbl's with moly & another great place is the front of cylinders & the top strap/forcing cone area. Man these areas clean up so much faster & easier.

Yes I still get some leading in my bbls. It just takes alot longer to have them lead up & there easier to clean.
 
As I said, I don't know much about moly, so I started looking at some information on the web and found this. Take it for what you want, I'm still not an expert.
RSI - More On Moly
 
Well I used some Kroil to try and break it up and the J-B Paste on the 624 and the Flattop Mag. Going to go to the range to check the results of my labor.
 
Ok things are a bit better. I tried 6.7 of Unique with a 240RN in the special and 8 of Unique with a 240SWC in the mag. 50 rounds through the special and 60 rounds through the mag. Both bullets are from the now defunct National Bullet Co.,I got these before their quality and service went down the tubes.
These bullets measured @ .430 and pass through the cylinders fairly easy. So I might try to up the load a bit to see if they bump up a bit to seal the bore. If not I will be looking for some .431 size bullets.

Accuracy was decent for me @25 yds and stayed consistent through all the shooting. It would probably be better once I get an eye exam and new trifocals. I still have some minor leading in the first inch or so but it brushed out easily when I got home.

I still have the Super and Ruger 44 Spec to cleanup with the J-B paste then see how they do.
Looks to me that you either go moly all the way or not at all,just don't mix them up.

Still have about 30 loaded of each caliber,maybe every once in awhile I will shoot a couple of them to use them up.

My thanks to all for the comments and suggestions to help me with this.
 
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