Moly bullet question: Moly residue? Affect non moly performance?


January 24, 2004, 03:51 PM
I'm reloading for a .300 WM., 26" stainless barrel.
I'm trying different bullets, and bought a box of 168gr. A max moly coated from Hornady.
If I shoot moly coated bullets, does the performance increase according to how many moly rounds go down barrel? Is there a moly residue I need to scrub out before using a non moly bullet?

This bullet says "twist rate 1-12". What's that all about?

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Steve Smith
January 24, 2004, 04:28 PM

Yes, or, just shoot and allow a few poor shots until the bare bullets settle.

Twist rate dictates the weight of bullet the barrel will stabilize. A 1:12 SHOULD stabilize 175s and maybe 180s.

January 24, 2004, 04:51 PM
I was hoping you'd weigh in.

When does shooting Moly coated bullets make sense?

The Tourist
January 24, 2004, 09:00 PM

You might try this for cleaning, I stumbled onto it by accident.

There is a cheap polishing wad called Nevr-Dull. It is just great for polishing brass. Try it on your Buck 110 bolsters and it will scare you.

I had just read an article on polishing barrels, fire-lapping, etc. Since Nevr-Dull works so well polishing cosmetic metal, I wondered how it would work on rifling.

I tore off a bit to form a tight jag and cleaned a pistol. Yikes! Even the lino came out! It works well cleaning the crap out of a .22LR after several rounds on a Sunday afternoon.

I figured it's cheap, it's easy, it doesn't feel as agressive as a Lewis Lead Remover, so I make it a part of cleaning every so often. If nothing else, the shiny lands and grooves LOOK nice.

January 24, 2004, 11:32 PM
I've used it in a marine capacity for years...hmmmm.
But I remember smelling amonia with that stuff. NOt that that's bad, just has to be cleaned out thoroughly..

Thanks for the tip.

January 25, 2004, 10:35 AM
Moly does not make sense to me in a gun that will be shot a little! The risk vs reward is simply not there! Once you instill moly into a barrel you are sort of stuck! Most of the custom rifle artist do not endorse the use of Moly. In the 223 I do use it. I use the a method of cleaning that uses Kroil. I shoot the 223 allot! And, if you do a good clean job; I encounter some POI changes till the barrel settles back in. And, that is a few shots. So, for something that you need COLD BARREL CONSISTENCY, Moly is not an option. I only shoot moly in the 223. In the 243 I stay naked, and the same with the 308. I tried shooting moly coated cast lead slugs long before it was popular. I appreciated no real difference in pistol rounds. But, there was not so much smoke as you can from cast lead lubricants.


Steve Smith
January 25, 2004, 12:09 PM
P0832177, I can't really agree with you. If you only use moly in a barrel, you won't lose cold barrel accuracy...only if you switch back and forth. Many of the best Highpower shooters use it. Many don't. Most can't tell a difference, and of the few that can, most of them will admit that the benefits are minimal. I have not been using it in my Highpower guns (except my NTIT gun...the CO State team does use moly for this load), but I will this year for one rifle. I have a new barrel with a 1:6.5" twist for shooting .223 90 grain JLKs. In order to keep the pressures low with this very heavy bullet AND to push it fast, moly is practically required. This gun will only have moly through it.

In my opinion, moly isn't necessary or even preferrable unless you have a specific need, and that need involves pushing pressure limits.

The Tourist
January 25, 2004, 01:03 PM

As for your ammonia concerns, I can vouch for the fact that they are slight, if existent at all.

After I clean brass bolsters, I just wipe off the vertigris with a clean rag.

After cleaning the barrel of any firearm, I just wipe it out with a clean patch.

I have NEVER found oxidizing, vertigris, pitting, rust or corrosion on ANY implement that I have used it on.

Rather, there appears something I refer to as 'dry lubricity.' Nothing has really been oiled, but the brass bolsters of a knife freshly treated seem to stay shinier than anything else and it is dry to the touch.

My 629-5 heavy lug barrel gets the Ner-Dull the most, and it's barrel gleams.

January 25, 2004, 08:18 PM
FWIW, I have a friend, Emil Praslick, who shoots/coaches on the Army Marksmanship Unit team. I specifically asked him about moly coating, and his reply was that unless you were willing to commit to a VERY SPECIFIC cleaning routine it can cause trouble. He also said that, in general, shooting moly is much more trouble than it is worth. The AMU wins a whole lot without it, and I guess that is a good enough reason for me to avoid it, along with the potential problems it's use creates.

Steve Smith
January 25, 2004, 08:26 PM
Emil is arguably the best Service Rifle shooter in the country right now. His comments are correct. Moly is only good for specific needs.

January 25, 2004, 10:51 PM
Emil is arguably the best Service Rifle shooter in the country right now. His comments are correct. Moly is only good for specific needs.

Wow, I knew he was doing well on active duty since he went back in, but not THAT well. He must have left that out of our conversation when I was asking him for some advice. Good guy, I owe him for giving me the Highpower bug when he was living in Minnesota.

Steve Smith
January 25, 2004, 11:25 PM
Well, there are a few others, like Jerome Bostick, Julia Watson, Chris Hatcher, Grant Singley...and on any given day any of them could be "the best" but they are all practically equal...ALL hard holders the likes of which you and I can't even conceive.

January 25, 2004, 11:35 PM
So now I understand Moly :

Is used for specific reasons, like reducing high pressures in some loads
Needs its own cleaning regimen (like what exactly?)
Maybe isn't for everyday shooters Why?, Expense? Extra Cleaning?)
Can cause lots of problems (like what exactly?)

Today I shot 5 different bullet loadings. The most accurate was the 168gr Amax Moly coated by Hornady. I shot misc. non Moly rounds after I was done with the Moly just to see if there were any differences. The first three rounds were wider than they should have been, but it did settle down after that, resuming the submoa with 180gr. sierra spitzers.

I just want the best accuracy out of this rifle. I'll stay away from the moly in all likelihood.

January 26, 2004, 04:11 AM
Well, there are a few others, like Jerome Bostick, Julia Watson, Chris Hatcher, Grant Singley...and on any given day any of them could be "the best" but they are all practically equal...ALL hard holders the likes of which you and I can't even conceive.

So I shouldn't feel bad that he kicked my butt at the matches he brought me to in Wisconsin??? :eek:

Also, not to hijack the thread, but Steve, Emil was telling me about an AMU clinic that is put on just prior to Perry and said that I should go to it, are you familiar with that clinic? I am really considering going.

Steve Smith
January 26, 2004, 08:56 AM
We all have different opinions on the SAFS (Small Arms Firing School) at Perry. It is really for people who have never fired a match before. Personally, I feel that a person should be a classified shooter to attend the Nationals, but that is not the way it is done and therefore there is a school at the beginning to help get folks up to speed. It works, to a degree. For a seasoned shooter, it is most likely a waste of time. I haven't attended but all reports say that you'll spend most of the day (8+ hours) waiting, and you'll fire 30 rounds. My suggestion is to shoot several matches and get used to pit changes and the like, get classified, and skip SAFS. Of course, just because Emil is a great shooter, I don't have to agree with him on everything, and we have disagreed before on participation at Perry. This is a minor issue and has nothing to do with our agreement on the practical parts of the game, and I am smart enough to listen when he says something in regards to that.

Moly cleaning isn't too hard, from what I can tell so far. If you insist on getting clean patches you'll be cleaning forever, but you're not supposed to do that. You don't use a brush (except in the throat as usual) and some good cleaning solvent does the trick.

It isn't for everyday shooters because it just isn't necessary, and it adds significant cost to reloading. Some people will site longer barrel life, but moly can't prevent the flame cutting at the beginning of the throat, where you will see accuracy drops first.

I don't know of any "problems" that moly creates, as long as you prevent a buildup in the chamber/throat area, and the obvious change of impact when going to a non-moly bullet.

January 26, 2004, 09:48 AM

I shot a few matches with Emil while he was in Minnesota training police, and I only shot sharpshooter both times with borrowed equipment and a borrowed rifle, so I am obviously not going to go to Perry and win the President's 100 or anything, but I have spent quite a bit of time in the pits pulling targets, so at least I'll be good at something if I head to Perry. :) I do have to admit that I was suprised to hear that people show up at Perry that have never shot a match before.

Emil also told me that the small arms firing school does not let you use your own rifle anymore, as too many High Master shooters were trying to sign up and get their zeros, so now they have you shoot with a stock M16 and issue ammo. Either way, I will likely go out to Perry early just to get some chess in with Emil. I am pretty sure I only ever beat him once, and that was up at Camp Ripley so alcohol may have been involved, but I am a sucker for punishment. Emil is still a chess legend at O'Gara's tavern in St. Paul. Well, infamous might be a better description. :p

January 26, 2004, 12:47 PM
Steve far be it from me to say it is bad to moly coat your bullets, but as you pointed out it is sort of application specific. In the 223 it works well for me! But, I will not shoot moly coated bullets in my 308 or 243. That is just me!

Perhaps a better way to use moly is that once you go down that avenue, you are sort of married to that bullet treatment. Moly is hard to remove, and it certainly makes no sense to flip flop between naked and coated rounds in the same range session as you will layer moly upon copper upon moly.

Moly is not for the finicky! If you use it then let it be! I have no real qualms with it! But, for the life of the barrel you are sort of married to it! David Tubb's Methodology for Moly Cleaning (

January 26, 2004, 12:59 PM
So if you use moly to get the velocity you need with a heavy .223 round at 600, then you have to moly your 200 and 300 yard ammo as well, right? It is not legal to switch uppers, so you would have to shoot out of the same barrel unless I am mistaken. From Steve's post I can see where it would make sense to moly with .223 if you were shooting 1,000 and needed to increase velocity to stay supersonic without going too high in pressure, but it still just seems like adding one more variable, a variable that someone like me really doesn't need, into the equation when talking about shooting OTC.

Steve Smith
January 26, 2004, 04:03 PM
P0832177, now we are in 100% agreement!

Goalie, most competition AR bullets don't have a problem staying supersonic, but it's the tim in flight you're fighting.

The ONLY reason I switched to it was to shoot 90's. I'll use them at 600 and possilbe at 800, 900, and 1K if I have the time this season. I would really like to clean the 600 line this year, and the 90's could save me the point or three I always seem to drop at the beginning or end of a wind shift. The 90 JLK is very similar to the 6mmBR in wind performance. I am just wanting to play with this, so I accept the PITA that the moly will add. Yes, I'll have to use moly for my shortline loads as well, but luckily I have a low-cost source for these, so it won't hurt me too badly.

January 26, 2004, 06:15 PM
This thread cleared up the reasoning behind using moly for me. Thanks for starting it Buckskinner, and thanks everyone else for the info.

January 26, 2004, 06:51 PM
I have been using moly for quite a few years now and I have found that with factory production barrels or barrels damaged by corrosive ammo that moly is a God-send. You would not believe how it cuts down on copper fouling build up. What used to take me a week now only takes me a couple of days to clean out all the copper fouling out of damaged military barrels or rough factory sporter barrels.

Remember its copper build up that makes your groups open up and the longer you prolong the build up of copper, the more rounds you can shoot before your groups open up. Moly has no equal in this regard.

If on the other hand you have a very expensive match grade barrel that has been of course been lapped smooth by the maker you may not need moly at all. Not all of us have super expensive match grade barrels on all of our weapons so for me moly is often a must.

I so occasionally switch back and forth between moly coated bullets and non-moly coated bullets and have had no problems whatsoever.

Moly is not hard to remove at all with ordinary solvents like Hoppe's no. 9. Although if you are a perfectionist and what to get all the moly out it will take a little longer, but the question is why would you want to remove it all anyway. Simply shooting the gun with un-coated bullets takes it out anyway.

January 26, 2004, 09:07 PM
I guess the proof is in the pudding...

January 26, 2004, 10:12 PM
That includes a Krieger-barreled M14NM, Colt Competition HBAR, Remington 700PSS, and 6.5-06 Interdiction wildcat, and WWII Remington 1903A4. I competed for several years with the M14NM at High Power matches, and the gun never experienced any ill-effects from the moly coating of bullets. Neither have the others. For a time, before I just got lazy, I moly-coated ALL of my centerfire jacketed handloads, to include 7.62x39, 7.62x45, .30-30 Win, 8mm Mauser, and .32 Remington. Once I find some extra time, I will get back to doing that. My old 8mm Mauser barrel looks like 20 miles of bad road inside, and the moly coating did indeed keep things from coating the insides. I'd change the barrel, but it shoots so well...

The most noticeable difference happened in my 1000-yard 6.5-06, which I always ran on the ragged edge of pressure, using thick RWS 7x64 Brenneke brass. It had a beautiful Krieger barrel, but was always laying down copper fouling in the last inch or so of the 25" barrel length, be they Sierra MatchKings or Nosler Ballistic Tips. The 3200+ fps probably contributed most to the copper fouling. Moly took care of that, and also dropped pressure signs on the brass. I make no attempts to remove all of the moly in that barrel during my cleaning sessions, and will continue to use that technique as long as I have a few pounds of lab-grade moly disulfide powder at my bench. :D

Moly will deposit elsewhere in gas guns, by the way. The piston face of my Bulgarian AK shows a thin coating of moly after about 60 rounds or so. Same for my M1 Garands. I'm sure if I ever take the gas tube out of my AR-15 or AG42B Ljungman, it'll be there, too.

January 26, 2004, 10:42 PM
...pounds of lab grade moly disulfide powder???

pounds? isn't that a lot? You only need a few ounces to coat bullets.

January 26, 2004, 11:02 PM
I think when "problems" are mentioned they are referring to the inability to switch from moly to non-moly coated bullets without a serious zero change and loss of initial accuracy. Is the biggest factor in the positive experiences here is that the use of moly coated bullets is exclusive, or are you guys having good results switching from moly to non-moly in the same barrel?

**Deep breath**

OK, before I get a wild hair and start another process I am just going to go work up the 2 loads for OTC I got from Emil and call it good.

Steve Smith
January 26, 2004, 11:16 PM
am just going to go work up the 2 loads for OTC I got from Emil and call it good.

Good idea. It's much easier to have a load that shoots well than it is to shoot the gun well. Get a good load and then get to work shooting.

January 26, 2004, 11:32 PM
pounds? isn't that a lot? You only need a few ounces to coat bullets.

You could say I found a lifetime supply, regardless of how many bullets I want to moly-coat. ;)

It even has a NSN (National Stock Number) on the bottle. :D

Nando Aqui
March 19, 2004, 08:16 AM
Oops - I was not familiar with the downside of moly-coated bullets, and had been using BlackHills 168-gr MOLY for higher-than surplus ammo accuracy. I used to reload many years ago, and I still have my RCBS press and collection of dies, scales, etc., but just don't do it. I have been getting the BH-moly from DSA at a reasonable cost (about $15/box) and this was affordable for me.

Fortunately, the BH-moly is all I have used on my Rem700PSS - safe there.

Unfortunately, I have switched back and forth a couple of times with my SA58 and M1A without cleaning in-between or following any special cleaning practices afterwards.

1) Can the moly be detrimental to the barrel, and if so, how?

2) If I want to compare how a rifle does with match-ammo vs. surplus*, would it be better if I just bought non-moly ammo for the comparison? (I have about 14 boxes of the BH-moly left.)
* Aussie and Port, which have been great, BTW.

3) I will keep using the BH-moly that I have on my Rem700PSS, and that is fine - but what should I do to preserve the other rifles that once or twice (maybe 20 to 40 rounds) had moly-coated bullets travel down their bores?

Thanks for your help!


March 19, 2004, 12:26 PM
I have a few questions, too.

Are the experiences with .223 translatable to .308? I'm cleaning with Sweet's over a few days' time, ending each session with Break Free to *perhaps* break things loose overnight. Haven't bought any Kroil yet, but I've heard that's the stuff to use after Moly.

I have moly on my plinking/practice bullets, and they will do about 2 MOA and my hope is to minimize barrel wear, especially when the kids are hosing cans at short range. The POI seems to be a good 3-4 inches away from naked 168s, at about 2 o-'clock, at only 100 yards. Can't really say how many rounds it takes to settle down the group sizes though.

After cleaning, does it really take only 3 or so rounds of bare bullets to stabilize group sizes in a .30-bore rifle? And how much does it change--POI drifting into the new group center, or random, and how many MOA?

After cleaning, how many rounds does it take for the moly bullets to stabilize group sizes in a .30-bore rifle? Again, how much change--POI drift or random, how many MOA?

Ultimately, I plan to get cold-bore data on both bullets. I'm right now a two-load guy.

edit: BTW, I'm using an Armscorp "NM" medium-heavy barrel (profile is slightly heavier--not cylindrical-- only from the chamber to the gas cylinder area), which I believe is NOT comparable to a Douglas or Krieger or Hart or whoever is popular these days. But it's done 1 MOA 5-shot groups at 200 with irons.

Steve Smith
March 19, 2004, 12:55 PM
It is translatable, just not directlytranslatable. I would expect to run 10 rounds through before I trusted the new zero. Each rifle being a law unto itself, one must only take stuff like this as a guide, and then see how closely your gun fits. No one can tell you what yours will do. Some time with the rifle will tell you everything.


Nando Aqui
March 19, 2004, 01:09 PM

Paraphrasing one of my earlier questions related to using moly-coated and uncoated bullets - -

1) Can the moly be detrimental to the barrel, and if so, what can be done about it?

Or is it just a question of a change in POI until the moly is gone?



March 19, 2004, 01:13 PM
I believe you have to shoot the same rifle over the course, and switching uppers might get you a protest in a serious match.

I think if you aren't going to shoot moly exclusively, then stick with traditional uncoated bullets. If you want to do side-by-side of match vs surplus, then I'd stay away from moly for the time being. Besides, there aren't many people who will claim that moly will yield better accuracy. Most folks I talk to say that it's benefits are found elsewhere.

Personally, I've shot moly for 2 or 3 seasons now in an M1A. I clean w/ Kroil and a nylon brush. At ~300rds, I use solvent and JB Bore Paste and work the barrel back to bare metal. Don't bother starting w/ moly unless the bore is completely bare of copper and other fouling.

I don't see appreciably changes in POI after cleaning, but my first rounds are usually shot offhand, so take that for what it's worth. I shoot high 90's offhand and my call is generally 1MoA or a little better. I usually run a patch w/ alcohol followed by a dry patch before I fire. Anyways, any change in POI due to cleaning would be 1.5MoA, but probably less--I'm thinking 1/2 MoA is a better guess--for the first 2 rds. If starting from bare metal, you might see some variation in the first 5-10 rounds, but I typically am not in a position to observe that personally.

The potential downsides of moly:
Some folks say they get an excessive buildup of moly at 300-500 rounds which will degrade accuracy, but this claim is debated among the guys who shoot it a lot. This is the reason for the JB paste cleaning I do, but I haven't left it in longer than say 400 rounds to confirm or discount this statement.

Some folks say that it attracts moisture and can lead to pitting. This is also tied in with concerns that sulfuric impurities in the moly will lead to localized acidic areas, again leading to pitting. My bore is definitely pitted, but let me also say that I had a saltwater aquarium for 2 years that was evaporating 1-2 gal of water a day, so that would definitely be a factor. Personally, I think that moly and a moist environment make a situation ripe for corrosion. My recommendation: if you shoot moly, get a coat of oil in the barrel ASAP after shooting and keep it there until you're ready to shoot again. If you do this, you shouldn't have a problem. BTW, I wouldn't use Kroil or other penetrating oil as a rust preservative. The protective barrier that it provides against O2 does not remain intact for more than a couple of days IMO/IME.

Quick cleaning & longer period of accuracy between cleanings. It will give you lower velocities, but the corresponding decrease in pressure will be more. This can be used two ways. First, keeping the powder charge the same will yield a longer barrel life (Tubb estimates something like 20%). Second, increase the powder charge and eventually get higher velocities for the same pressure that you would have with uncoated bullets.


Steve Smith
March 19, 2004, 01:15 PM
I'm not expert, and just beginning my experience with it, but I do have a ton of friends that use it. Moly is, if anything, good for the bore, in that it theoretically increases barrrel life. This is a secondary (if anything) benefit.

March 22, 2004, 02:10 AM
steve, so far only moly'd 69 gr smk's have been fired out of my 223 bolt gun. If I want a 1000 yd. 80 gr SMK load should I go with moly? If I don't have to, after my current batch of moly'd 223 runs out I'd like to permanantly cease using the stuff, but if I need it...


Steve Smith
March 22, 2004, 09:30 AM
Folks have used 80s at 1K with mediocre success. The 90s are what allowed the AR to start beating the M14 at that distance. For 90's, moly is almost a requirement (one guy I know does not use moly, but uses staked primers instead). You can push 90s HARD with moly. For 80s, I just don't know. I think you are already looking uphill.

March 26, 2004, 04:49 PM
Not really looking for a 'competitive load', just looking for something that will stay supersonic at 1k. But if 80 gr. won't do it, I'll have to wait til I've shot out the barrel out of my tikka before I try any long range stuff.


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