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MOLY COATED OR NOT ???
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<FAINA>
posted
Hi friends,
I have a question for expert-reloaders:
I have a good load for my 30.06 and for my 7mm Rem mag, this are with normal bullets. If I want to use the same bullets but moly coated how much powder I must to add? What is the diferent (velociyt and pressure) if I use the same load?
Thank all can give me an answer.
ciao FAINA
 
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<Rem700fan>
posted
I do not have a set formula. The best thing to do when changing any component of your reloads is to start over and work up the most accurate load for your rifle.
 
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<David>
posted
I did quite a bit of testing with a 7mm STW last year. I found a few things.

With the same load and bullet, the moly coated bullets was about 100 fps slower. It took about 3% more powder to recover the lost velocity. I could get a little more velocity with the moly coated bullet, but not enough to justify the extra powder.

Moly coated bullets just give you another set of problems cleaning the barrel. None of the solvents on the market will act on the moly. You end up with alternating layers of moly and copper that are a pain to clean.

No noticable change in accuracy.

This was all done in 15 pound blueprinted Rem 700 in a McMillan Tooly MBR stock, Select match grade 28 inch barrel.

My conclusion - don't bother, moly is not worth trading one set of problems for another.

 
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<PowderBurns>
posted
I'd be curious. What's the "theory" behind moly coating? I think it's a lubricant. Am I wrong on that?

------------------
PowderBurns Black Powder / Muzzle Loading Forum:

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

 
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<short243>
posted
While there are lots of conflicting stories on moly the bottom line is it is supposed to extend barrel life. That said, tried it in a custom 243 put together for hot little bullets and decided that was a mistake, true I had longer strecthes between cleaning but the accuracy went way south for 12 to 15 rounds afterwords. In a 308 that I dearly love to shoot accuracy came back after cleaning in 3 to 5 rounds, this is a mild load though and no where near warm. So no need to moly coat there and the extra rounds on a hot load to get back where I started, figured I didn't the headaches of cleaning it out of the barrel, that is work...
 
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One of Us
Picture of Zero Drift
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Ditto Rem700 - The best and safest thing to do is to shoot over a chronograph. A chronograph will tell you everything you need to know. There is no set or safe formula. In almost every instance, I have noticed a velocity drop with moly. This is due to less friction and lower chamber pressures. You would logically think the opposite - less friction and higher velocity. Not so with lower chamber pressure and powder burn rates.

Just as with any reloading, start with the minimum load tables and work up. To achieve targeted velocities, you may find yourself above the maximum load tables. Keep looking for pressure signs and just make sure you do not switch back to copper jackets for the same load - very bad things can happen.

If you decide to shoot moly, make absolutely sure ALL copper is out of your barrel first. Sweets or CR-10 your barrel very well. You do not want to trap copper between your barrel and moly.

Z

 
Posts: 10780 | Location: Test Tube | Registered: 27 February 2001Reply With Quote
<Rust>
posted
Every rifle reacts to moly differently because of minute (or not so minute) variations in freebore, leade angle, actual land diameter, actual groove diameter, number of lands, ratio of land surface area to groove surface area and pretty much anything else.

I have several rifles with factory barrels that responded very well to moly, and several with custom barrels that don't seem to care. One factory rifle shoots phenominally well with moly, and is marginal at best without moly.

I have some advice for getting started with moly: first, the barrel must be completely clean, no copper or powder fouling should be left in the barrel; second, the barrel should be pretreated with moly, I use a commercially available oil/moly mixture, coat the bore with a wet patch of the stuff, and then run a dry patch to remove the excess; finally, moly by itself is a lubricant and posseses almost no preservative properties and so will not prevent corrosion, use the oil or an oil/moly mix to protect you barrels when you put your rifles away.

Moly is not a cure all for every rifle, and can adversly affect accuracy in the occasional rifle. The main thing is to determine how moly works in your rifle and whether the perceived benefits outweigh the additional trouble.

I have never considered velocity in developing loads, only accuracy. I just load within safe limits to find the most accurate load, and primarily chronograph to determine spreads, averages and deviations.

 
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<FAINA>
posted
Hi friends,
thank for all your informations.
Next time I'll probe some loads with moly-coated bullets in my rifles.
ciao FAINA
 
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one of us
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Berger Bullets in their FAQ has the basic steps to breaking in a barrel and cleaning a barrel while using moly coated bullets:

http://www.bergerbullets.com/faq.htm

Steve

 
Posts: 439 | Location: Kansas by way of Colorado and Montana | Registered: 04 April 2001Reply With Quote
one of us
posted Hide Post
Hey FAINA, I've used Moly for quite a few years now and will continue to use it until something better comes along. Putting it on the bullets can be a bit of a hassle, but for me, it is worth the effort.

If you decide to Moly Coat your own bullets, one tip I can give you that is hard to find out about is to "wash the bullets first". Some of the bullets we get are pre-washed and some are not. Any forming lube that remains on the bullet will make it difficult for the Moly to adhere properly.

I use Procter & Gambles "Dawn" dishwashing detergent in real hot water to cut through the oil. Let them soak for 20-30min, rinse in hot water and let dry in the sun. Then the Moly will go on easier and coat better.

One other trick concerns case prep. After chamfering the mouth, polish the mouth with "0000 Steel Wool" wrapped around a Bore Brush. Use a big enough piece of Steel Wool so that both the inside and outside of the case mouth jams into it. Just turn it by hand on a handle. No need to spin it in a drill. This keeps the case mouth from "stripping" the Moly off the bullet as you Seat it.

Here is the best article I've ever seen about Moly. It is long and quite detailed. Be sure to notice the amount of bullets through the hot 6.5mm with "no discernable loss of accuracy".

www.precisionshooting.com/aug98.html

Oh yes, one last thing. When you get through shooting. Clean the barrel and oil or grease the bore as you normally would with any rifle. Moly does not protect the barrel from moisture as some lubricants do. I use a Moly grease in my barrels after cleaning and it works fine.

Good hunting and clean 1-shot kills, Hot Core

[This message has been edited by Hot Core (edited 04-22-2001).]

 
Posts: 9920 | Location: Carolinas, USA | Registered: 22 April 2001Reply With Quote
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