Moly bullets go slower with the same charge as non coated bullets? Can anyone tell me why?

Also, what about corrosion to the bore and moly coated bullets? Are they worth the extra effort/expense? What sort of increase in accuracy might I expect?

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PowderBurns Black Powder / Muzzle Loading Forum:

www.hotboards.com/plus/plus.mirage?who=powderburns

Velocity decreases because pressure decreases with the use of moly coated bullets. You, therefore have to increase the powder charge to maintain the same velocity.

The moly residue if left in your barrel and combined with water will create a corrosive solution.

There is no real indication that coated bullets are more accurate than non coated. Some say that since the bullet experiences less friction that it is therefore deformed less and thus more accurate. I would say that even if that is the case the difference would be unperceivable in most rifles.

The advantages to using moly coated bullets are less fouling (thus less frequent cleaning)and less barrel heating (thus less barrel wear).

Here is my take: Unless you are shooting in a situation that requires you to shoot lots of rounds without cleaning don't bother with moly bullets. If you do use moly bullets never put your rifle away unless it is thoroughly cleaned.

For instance: I do not use moly bullets in my hunting rifles. I do use moly bullets in my silhouette rifle because it's a 40 round match with probably 10 or 15 sighters prior to the match. I do use moly bullets in my prairie dog rifles because of less barrel heating and less frequent cleaning (with moly coated bullets I clean every 50 rounds or so vs every 15 or 20 with non-coated.

Hey PowderBurns, I use Moly on very bullet I shoot. So, I consider the extra effort to coat them is well worth it for me. But, if a person doesn't really shoot a lot, then it probably just isn't worth the hassle to Moly Coat.

Mike brought up a point about barrel corrosion that I'd like to expand on just a bit. Water in any steel barrel, whether it has Moly in it or not, will cause corrosion!

For some reason completely unknown to me, somewhere the idea has gotten started that if you use Moly Coated Bullets that you do not need to clean your barrel - that is wrong! You always need to clean your barrel and then apply a light grease or oil to the Bore. If this is done when you bring the firearm back in the house, you will have "zero" corrosion problems. Don't clean, and whether or not you use Moly, eventually you will have a pitted barrel. Or, at least that is the way it is here in the high humidity of the Southeastern USA.

By the way, here is a link to the very best article I've seen on Moly. It takes awhile to read through it, but be sure to check out the number of those "hot" 6.5mm that Norma put through the barrel with no discernable loss of accuracy.

www.precisionshooting.com/aug98.html

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Good hunting and clean 1-shot kills, Hot Core

Sound advice all around. Moly had its good points and bad points. I use moly bullets on several guns. I have had the most luck with smaller caliber, high velocity cartridges. Moly is no cure all for accuracy. Some guns like�um some guns don�t. There is a lot of misinformation regarding moly - as you will find.

Here are a few considerations -

1. If you have a new barrel, you should follow a regimented break in procedure. This is for different reasons than the normal break in reasons/arguments. Shoot one and clean till 10, then shoot 5 and clean till 20. This is to evenly deposit/burnish moly into the barrel and avoids trapping copper between the barrel and moly. I use Moly Bore Prep for the first 10 shots to ensure that I get an even coat. Midway carries Bore Prep - 800 243-3220.

2. As Mike and Hot core stated, cleaning and rust protection are still needed with Moly. The cleaning process is a little different than copper in that you use Kroil to loosen excess powder fouling and moly. JB bore paste is used to clean the fouling in the throat area of the chamber. Molybdenum Disulfide does NOT break down to form acid that eats your barrel, but you do need to protect your barrel.

3. If you have shot copper bullets and want to try moly, clean your barrel completely. Use Sweets or CR-10 to ensure that every trace of copper is out of your barrel. You do not want to trap copper between your barrel and the moly. If you shoot moly and decide to go back to copper, no big deal. Clean with Kroil and JB to remove most of the moly. Some moly will stay in the smallest of imperfections in your barrel.

4. Velocity will drop to lower friction which does reduce pressures. You need to shoot across a chronograph to work your loads back up to the desired velocity. You will exceed max charge weights if you want to obtain max velocity. This may cause a few heart flutters, however, monitor pressure signs and note velocity changes.

5. While you can purchase moly kits to coat bullets at home, I would suggest that you start with factory coated bullets first. Just about every manufacturer offers moly as an option. I have had great luck with the Combined Technology bullets from Nosler. The Partition Golds are a little tougher than the standard Partition and perform extremely well in the field.

You may want to give them a try, however, don�t be frustrated if your gun doesn�t like them - it happens.

Z

[This message has been edited by Zero Drift (edited 06-28-2001).]

Let me clarify my previous post.

I am not advocating putting a rifle away dirty. I simply mean that you can fire more rounds through most rifles before the barrel fouls to a point where accuracy is affected when using coated bullets.

There are different opinions about "moly corrosion". I recommend you go to Varmit Al's web site and look at the tests he ran.
Just out of curiosity I ran similar tests and got similar results. While I would surely not deem these tests to be "scientific", they certainly should make one wonder.

The reason why some rifles "like" moly coated bullets and some not, is harmonics. It is the same reason why a rifle shoots accurately with some bullets and not with others. The more you reduce the pressure peaks and vibration, the better a rifle will shoot. So if a rifle shoots with a particular bullet, but does not, when that same bullet is moly coated it is because the harmonics have changed. All that is needed is to adjust the col of the moly coated bullet till the grouping is restored.

There are several different grades of moly available. The cheap ones will react with water and rust the barrel if not meticulously cleaned. The more refined grades are inert and will not do that. You get what you pay for.

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Gerard Schultz
GS Custom Bullets