To Moly or not to Moly

A

Andy Cross

Guest
Some people are sold on the idea of using moly coated bullets. Others say not. Although my major was in physics ( optical engineering ) not chemistry I still have a good working knowledge of that subject.

Cleaning a barrel to remove the copper and powder fowling is vital in maintaining accuracy. I can't see that any component in the solvents available today will dissolve molybdeemum disulfide. So my guess is that it is just allowed to build up. Some say this build up doesn't matter others say it does. If the build up doesn't matter then why when any other build up does. If it doesn't build up then again why as there isn't any thing in the solvents that will break down the moly.

I hope someone can shed some light on this issue but please back it up with facts.

Regards,
Andy.
 
moly does one and only one thing: it allows a rifle to shoot the SAME accuracy LONGER( between cleanings) period.
testing done by lapua/nammo was published documenting this fact.
it is slicker( less friiction) than bare bbl.
the slickness leads to a larger initial combustion chamber( the bullet moves further earlier) leading to lower velocities if one does not adjust thier load for the change.

cleaning is different in that one does not want to disturb the moly coating....
so cleaning is done chemically and not with copper brushes.
use a carbon remover first, then a copper remover....patches and or swabs..no brushes.
time and chemestry are your friends.

having said all that do a search on HBN.
i have change to it in my 1000yd rifle.
mike in co
 
Last edited by a moderator:
Another alternative, that has received favorable reports is tungsten disulphide, which was once marketed as Danzak. It is my understanding that it had less tendency to build up in barrels. BTW I understand , from an excellent source, that Dawn dish washing detergent does an excellent job of getting moly off of and out of things.
 
I have been using moly in my Prairie Dog rifles for years. Definately get longer barrel life and accuracy may be better - it is definatley not worse. I do not get moly buildup. I clean with Wipeout every night after shooting several hundred rounds. Run a Kroil patch or two - two or three KG's or Butch's and a couple more Krios every 20 or so rounds during the day. I get some copper out of the barrels every night, but not a lot. Usually shoot a few hundred round a day using two rifles.
I don't shoot Benchrest except in 22's do I have no experience with moly in that game.

KG
 
Loads drop in velocity with moly coated bullets because of latent heat that is absorbed by it's vaporization. This drops heat/expansion, and so it does also improve barrel life a bit. While there is reduced bore friction in moly coated bullet travel, this in itself does not affect peak pressure to reduce velocity or increase barrel life.
Only it's affect on charge temperature comes into play here.

Moly does fill crevices that copper would otherwise get into, and the reduced jacket temps mean less expansion and jacket tearing. Some bullets can be spun up a bit faster and still survive, if coated.
Sounds great, but there are issues with moly..

Issue #1
Moly is fouling. A particular fouling.
Moly fouling in barrels has to be managed like any other, and if you do so, you'll never have an issue.
The trick is that initial moly prefouling takes 30-50shts to settle. Then you can shoot another 100+ shots easily without copper fouling out.
Then you chemical clean only to get fouling back to near the 50sht settle. Take too much out and it will take more shots to settle again.
Take too little, and moly builds up to issue #2.

Issue #2
Moly has an affinity for itself. It sticks & layers, smearing down a bore like shingles. The first 6-8" is flashed away with firing and then a bullet meets a buildup constriction of layering moly. If allowed to continually build up, this constriction will kill accuarcy.
Now it's time to deal with it, and eliminating a moly constriction -without ruining a barrel, is a nightmare that many failed with.
This is the strongest basis for moly falling out of favor.

Both of these issues can be managed. But I'm sure most shooters coating today have gone to better alternatives like WS2, or HBN.
I never went to moly, but watched closely while instead using WS2(tungsten disulphide).
From my perspective, WS2 provides all the benefits of moly, with zero issues that I'm aware of(and I've been using it for ~20yrs).
After I shoot, I clean my bores back to base metal, and then dry burnish prefoul with WS2. My bullets are always coated as well.
With this, my first shot is truly no different than any to follow. There is no settling to do.
I don't think I could hold peak performance with 100+ shots between cleanings. But I know 50 will never copper foul out, and I know exactly how to reproduce 50 more to follow.

I am 'watching' HBN now(better than HBO).
 
I can get behind mikecr on this one...... I think he's perty much covered it.

BUT, my 'answer' to the moly riddle is a liddle different, WHY BOTHER? Try exactly the same regimen with nekkid bullets. Clean with Montana Extreme Copper Killer (the red stuff, like BBS USEta' be....) using patches only, no brushing, and run head-to-head with moly. And no "settling in," your first shot after cleaning is right there.

try it!

al
 
Ok Boyd
- I clean my guns with them hanging off a step ladder, barrel pointed down, and I don't hold back on cleaning a bit.
- Then I dry the bore out with a washing(literally) of the best alcohol I can get my hands on. Right now, it's anhydrous 'Pure Ethanol'. I use a clean mop for this, short stroking while pumping alcohol in with a squirt bottle 90deg nozzle through the ejection port(no guide). It pours out the muzzle into a pan.
- Then I let it dry about ~1hr and verify so with a dry patch. Sometimes I blow dry it.
- Then I insert to the throat a highly technical prefouling guide(HTPG) /flared piece of automotive gas line. And lay a shop towel over the stock.
- Then I pull out a squishy plastic tube within which is dry WS2 coated BBs and a mop with it's threads pointed up, so that I can hold the mop(by squeezing the tube) while screwing my rod onto it.
- Then I run the WS2 mop through the bore ~10 full strokes ending with the mop out the muzzle.
- Then I carefully insert the mop(while at the muzzle) into that squishy tube and unscrew the rod from it.
- Then I drop ~1/8pinch of new WS2 into the squishy tube, put the lid on it & shake before storing(ready for next use).
- Then I push 3 dry patches through the HTPG all the way out the muzzle. The third patch would have light streaking only. I hit it with a little alcohol and wipe off the muzzle.

My bullets are also WS2 dry burnished, and after seated I give em a wipe with a shop towel that was saturated with turtle wax and dried(years ago).
I store all my guns clean, dry, & prefouled this way (even handguns).

Of coarse you're right AL. This ain't directly improving accuracy over nekkid bulits.
I did it initially to combat ugly excessive copper fouling factory barrels. I'm talkin barrels that couldn't be counted on for three 5sht groups without a dozen blue patch regimen!
I'm past that now, but I haven't a reason to stop prefouling.
And I like storing my guns dry.
 
Years ago, when I shot the late Jeff Fowler's Bullets, he told me if he ever heard of me moly coating them, he would not sell me any more. I never did.......jackie
 
I shoot 500 meter groundhog matches in a pure factory class with a Savage LRPV .223. I have moly coated my 80 gr. VLD's from the beginning to reduce bore erosion and extend the barrel life. Rules require that the barrel be original. I now have 1,800 rounds on the factory barrel, and it has lost some accuracy. I periodically check land contact and adjust my OAL. I am not certain the moly has been beneficial, but at this point I continue using it. I do not moly for any of my cutstom rifles.

I clean the moly out every 50 rounds or so. Hate to do that, because it then takes about 10-15 rounds before she regains her accuracy. In other words, the moly has to build up to restore accuracy. Tried HBN, but did not think it was effective. BTW, I am using moly bought 12 years ago from Midway. Stuff lasts forever.
 
Thanks for the view points

Thanks everyone for your input on the subject of moly. It seems as though as always there are pros and cons. Advantages along with disadvantages. I'll try moly out on the new .222 when I get it back from pseco. I've ordered two barrels for it and I'll shoot one with and one without moly keeping the number of rounds close to the same for each. This may give a more definitive comparison..

Andy.
 
andy,
the comparison has been done, in lab like conditions, with documentation.
the results have been published.
25% of the benefit is the wax, do not skip it.
it was done by one of the biggest well known companies in the industry.
lapua/namo.....
i believed they used 6.5x55 for the test.
it may still be on thier site.
mike in co
 
The 'Moly' argument will go on forever. I've tried Moly bullets and experienced no advantage with them. Other top rated benchrest shooters swear by them. I guess it all depends on one's experience with them. Try some Moly bullets, win a match, and the person probably sticks with them forever.

A friend of mine who shoots service rifle and is a 'High Master' shooter, experienced 5800 rounds before the accuracy went, with his first barrel shooting naked bullets. He switched to Moly with his second Obermeyer barrel and experienced about 5500 rounds before the accuracy went. No increased barrel life with his loads. He still shoots Moly bullets because of his belief that they do cause less fouling. This is very important in service rifle competition since they have no time to clean.

The 'Moly' argument has led to discussions citing 'expert' chemical and physics arguments, empirical arguments by experienced shooters, and company experiments. Yet the arguments go on. In my opinion the answer is to try a few hundred Moly coated bullets for one's self and observe the results. If you don't see any advantage, the barrel is easily cleaned in a normal fashion when you decide to go back to naked bullets.

Good luck...virg
 
virg.....
that is precisely correct...and THE WRONG DATA POINT.
moly provides the same accuracy longer BETWEEN CLEANINGS....there was no claim by lapua of increased bbl life.
again
moly provides the same accuracy longer between cleanings.
this is why high power shooters used it...they shoot a 88 round course of fire over the day.....accuracy stays all day.

mike in co
virg said:
The 'Moly' argument will go on forever. I've tried Moly bullets and experienced no advantage with them. Other top rated benchrest shooters swear by them. I guess it all depends on one's experience with them. Try some Moly bullets, win a match, and the person probably sticks with them forever.

A friend of mine who shoots service rifle and is a 'High Master' shooter, experienced 5800 rounds before the accuracy went, with his first barrel shooting naked bullets. He switched to Moly with his second Obermeyer barrel and experienced about 5500 rounds before the accuracy went. No increased barrel life with his loads. He still shoots Moly bullets because of his belief that they do cause less fouling. This is very important in service rifle competition since they have no time to clean.

The 'Moly' argument has led to discussions citing 'expert' chemical and physics arguments, empirical arguments by experienced shooters, and company experiments. Yet the arguments go on. In my opinion the answer is to try a few hundred Moly coated bullets for one's self and observe the results. If you don't see any advantage, the barrel is easily cleaned in a normal fashion when you decide to go back to naked bullets.

Good luck...virg
Click to expand...
 
You must log in or register to reply here.
Back
Top