If moly coating doesn't improve grouping, is it at least not detrimental?

[VaniB]

Thanks gents for all the input. I am normally capable of 2's and 3's 5 shot groups with my bolt actions. But this particular rifle with all my fancy rifle rest gear and carefully handloaded rounds can't do much better then 1" at 100 yards anyway. But, I certainly didn't want to use molys and see groups deteriorate from that, if even only slightly larger groups. 1" groups is about as bad as I can stomach, and it's only because it's a military style AR with a light 18" barrel and collapsible stock that I'll tolerate it. (ever try to sandbag a collapsible stock?) While I probably just lost the attention of about 2/3 of you guys now that you know what kind of rifle I'm shooting (and made a few of you serious benchies cringe just now too), I want you to know that I am using much the same methods as you bench rest shooters are using........and that includes using Lapua brass and weighing each bullet, using wind flags, feeding single rounds into the chamber, detailed note taking, etc. I have about 3 grand invested in building this rifle and intend to keep striving for tighter and more uniform groups.

From what I'm hearing, I doubt I will see much change between naked VS moly groups, and so I will likely continue to buy moly bullets only when I can't find the regular non-molys.



PS Thanks to you guys, now I also know that I'm likely not missing anything spectacular if I don't use molys for my precision bolt action rifles.

 

[J. Valentine]

It seems like whenever I need to order a Lapua bullet, the only thing I often find in stock is their moly coated version. I don't mind paying the extra few bucks, but I was wondering if the moly bullets will actually group differently. (ie; group worse) The same goes for Hornady bullets.

In case you ask, I'm shooting the .308 155 grain Lapua and Hornady 168 BTHP, and the 75 grain .224 Amax.

Have any of you guys noticed that the NON-COATED bullet has actually shot tighter groups for you then the MOLY COATED bullet? I don't mind if garnering any benefits with moly bullets is questionable/debatable and a small waste of money..... as much as I do mind if they might actually not group as well.








EDIT: ps....thanks, but there is no need for anyone to post me links of places that have the non-moly bullets in stock. This is just something I have wondered and need to know for future purchases. Thanks again.

It depends entirely on what accuracy test you intend to use to compare the coated and uncoated bullet.
If you intend to clean after every few groups then on average the naked bullets can show slightly tighter groups. The nature of the test favours the naked bullet.
If you intend to fire a long string of many groups without cleaning then on average the moly coated bullet will be more accurate . The nature of the test favours the coated bullet that is less effected by fouling.
It's the pattern of use that dictates wether moly is useful or not.
Also you may see slightly flatter trajectory at longer ranges than is predicted by ballistic programs.

 

[J. Valentine]

I have been shooting moly bullets in most of my barrels since 2002.

My experience is moly bullets are as precision as naked, but no better.

For the same velocity using the same case in the same barrel moly bullets need a little more powder.

I can shoot more rounds with out cleaning with moly bullets.

In my very high velocity barrels I have not had a problem with moly bullets blowing up before they get to the target. Same barrel same velocity I have had naked bullets blow up. Slicker barrels do work better in this special case.

I do get better barrel life with moly bullets. My barrels get rechambered and down graded to fun and field barrels for their later life. These older barrels will shot a long time when you only expect 3/8" groups.


With moly bullets the detail cleaning at the end of the day is a lot more work than with naked bullets.

I now suspect that some of the newer bullet lubs may be better.

This sound like a sensible man indeed.
On the issue of other coatings TD does infact have slightly better load bearing capabilities in the highest grades but in the lower grades is about the same as MoS2 .
TD does have better thermal stability and can take higher temps.
However it does not have the capability to build up like moly does.
Some have used this to make it seem like a negative for moly.
My research so far seems to indicate to me that it may be a neagtive for TD not moly.
The fact that moly can produce a thicker lamellar structure in the bore than TD could in my opinion cancel out the extra thermal capability of TD and make them fairly even .
However I am suspicious that this thinner coating in the bore may not protect the barrel as well as it first appears.
However on the issue of cleaning TD is much easier because it is thinner in the bore.
TD and Mos2 are similar materials.
The very reason that moly MoS2 works seems to be the thing that is used against it. The fact that some buildup is going on.
People seem to panic at the thought of a buildup.
If you clean to suit your pattern of use there is no real problem.

 

[Donald]

This is by no means a scientific test, but just an obseration. I have shot naked, moly and boron nitride coated bullets in a variety of rifles, mostly, 6ppc. Naked, you pretty much have to clean every target. Moly and BN you can go longer. But clean up then results in having to shoot about 10 rounds to "condition" the barrel. I see no difference in the accuaracy of either method. I have no doubt the coated bullets result in a longer barrel life. How much, I don't know. In short range BR in which we clean every 10-15 rounds there is no need, as I see it to shoot "coated" bullets. On the other hand if you are shooting a condition where you have to shoot 50 or so rounds without cleaning then there might be an advantage in shooting "coated" bullets. Since I shoot short range BR, I have gone back to naked bullets after trying both moly and BN.. And I clean between each target. JMO.

Donald

 

[KEITH MYERS]

I guess I'll proceed with using some "soft-scrub" cleanser on a few of my 155 moly bullets to remove the Lapua "silver" coating.

I cleaned one bullet last night and found the process to be a messy and time consuming PIA. But, I guess I'll get to see first hand with 7 or 8 bullets if there's any noticeable difference with grouping.

Try using rice in a vibrating case tumbler. It works great and rice is cheap.

 

[mike in co]

Thanks gents for all the input. I am normally capable of 2's and 3's 5 shot groups with my bolt actions. But this particular rifle with all my fancy rifle rest gear and carefully handloaded rounds can't do much better then 1" at 100 yards anyway. But, I certainly didn't want to use molys and see groups deteriorate from that, if even only slightly larger groups. 1" groups is about as bad as I can stomach, and it's only because it's a military style AR with a light 18" barrel and collapsible stock that I'll tolerate it. (ever try to sandbag a collapsible stock?) While I probably just lost the attention of about 2/3 of you guys now that you know what kind of rifle I'm shooting (and made a few of you serious benchies cringe just now too), I want you to know that I am using much the same methods as you bench rest shooters are using........and that includes using Lapua brass and weighing each bullet, using wind flags, feeding single rounds into the chamber, detailed note taking, etc. I have about 3 grand invested in building this rifle and intend to keep striving for tighter and more uniform groups.

From what I'm hearing, I doubt I will see much change between naked VS moly groups, and so I will likely continue to buy moly bullets only when I can't find the regular non-molys.



PS Thanks to you guys, now I also know that I'm likely not missing anything spectacular if I don't use molys for my precision bolt action rifles.

as has been stated, very well by some, the advantage of coating is to shoot the same longer. it is not an improvement in the guns ability to shoot , only to shoot the same longer.
its a shame to spend 3 grand on a 1 moa rifle.......but there may be an answer.
what is the bbl twist ?

the amax is longer than the 75 match and may need a different twist.

and what optics ?

mike in co

 

[goodgrouper]

A friend of mine was reading this thread about moly and sent me an email with an interesting analogy of moly. He said that moly and cleaning were a lot like shoveling the snow off the driveway. You can go out and shovel a little bit every so often until the storm quits, or you can go out and shovel the entire storm's accumulation after it's done. You will have shoveled the same amount either way but your back will hurt only with one method and not the other!

By golly, he's right!

You can clean every 25 to 30 bare bullet rounds and have a 15 minute job, or you can use moly and clean every 100 or 200 rounds and have a two hour marathon cleaning session afterwards. The choice is up to you! How's your tennis elbow?

 

[Octopus]

Cleaning with moly is not that big of a deal.

I usually clean about every 25-30 shots with Kroil.

At the end of the day, usually less than 100 shots I detail clean first with Kroil and then with JB Bore paste. I use a tight wrap round patch for 25 strokes with bore paste. Then I clean out all the bore paste with Kroil. Sometimes I use a second patch and 25 extra strokes.

My bore scope shows my barrels look like a mirror when I finish.

5 to 8 minutes.

It does take a tight patch to clean right. Much more rod pressure than most shooter use to clean.

 

[goodgrouper]

Cleaning with moly is not that big of a deal.

I usually clean about every 25-30 shots with Kroil.

I'm curious why you would even use moly if you are only shooting 25-30 shots? I go that long with bare bullets.

 

[Octopus]

Back in 2000 or so when I got my Panda Jim Boden at the time recommended Moly and the cleaning procedure that I use. One started I have continued.

Barrels last a little longer with lub on the bullets.

Usually I clean at 25 or so with Koil just to get the carbon out. Not sure it makes all that much difference with PPC and BR cases where I am using 32 gr of powder or less.

I feel it does help some shooting 6.5 - 284 and similar capacity cases where I burn a lot more powder each shot.

Again I suspect some of the new bullet lubs may be better than moly. Like someone said earlier I am still shooting up my older inventory.

 

[goodgrouper]

Barrels last a little longer with lub on the bullets.

I was told the same but none of my moly barrels lasted any longer than the ones I didn't run moly in. In fact, had one that seemed to burn out quicker than it should have.

Since the vast majority of heat generated in a barrel comes from expanding gases rather than the friction of the bullet on the barrel, and the temperatures of the gases far exceed the temps of friction, I don't see where moly could possibly prevent any measurable barrel wear. A coating on a bullet isn't going reduce the flame temperature of the gases..............In fact, since you usually have to increase the powder charge to regain a desired velocity with moly, you would actually be increasing the volume of gas and it's effects!

 

[VaniB]

as has been stated, very well by some, the advantage of coating is to shoot the same longer. it is not an improvement in the guns ability to shoot , only to shoot the same longer.
its a shame to spend 3 grand on a 1 moa rifle.......but there may be an answer.
what is the bbl twist ?

the amax is longer than the 75 match and may need a different twist.

and what optics ?

mike in co

To clarify.....it is the 308 AR rifle and 155 Lapua moly bullets that is the task and question at hand and the reason for posting this thread. My .224 bore bolt action rifle shoots tight and fine with naked 75Amax bullets fine. I only mentioned the 75Amax in case I find myself having to choose between purchasing the 75Amax in moly or no bullets at all in the future. Distributor inventories have been tight everywhere, and sometimes moly bulets are all that a dealer has available.

Yes, I agree with you that it's "ashame" that I can't get bettere then 1" accuracy so far with a $3,000 rifle. I'm still working on it. But I thought I would take this moment to show you what I'm dealing with:

Do you know what it's like trying to steady that collapsible stock on a leather rabbit eared bag? (or any bag!)

There's probably only so much I can expect out of this style rifle with a 2.5 pound barrel, collapsible stock, and quick detachable scope . I think that I'm still learning and finding out about how to hold that rifle. My bolt actions give me 2's and 3's 5 shot groups, but I also don't have to hold them the same tight way to control sliding bolts and springs.....as well as the lack of consistant follow through after each shot. I also refuse to load the cartridges at a longer length then the magazine. So....under these conditions and worthwhile sacrifices, I'll be happy to have a rifle that can consistantly shoot 1". I'll be tickled if I can get it down to 3/4" .

Such is the price I suppose to have a rifle that "does it all". It will hold 20 rounds of fast fire, can fire a high energy round out to 800 yards, or with the scope quickly pulled off, it can deliver close quarters shooting with the back sights instantly flipped up.

As mentioned in my post #21, I know this kind of rifle is not something that most guys here can appreciate, but the issue of attaining the best accuracy possible and what kind of bullets may be used to do so, is a common ground I share with you guys.







EDIT: Oh....to answer your question....It's a 6X-24X Elite 4200, and a 1-10 twist barrel.

 

[Octopus]

I use a block on the forearm, 3" X6"X.75" on my AR when I shoot off the bench. I have a block on the rear stock to better work with the rear bag. This make a big difference.

My Stoner 223 in M-4 16" barrel would shoot 10 rounds into 3/8" or less in five seconds with the blocks shooting off the concrete table with BR front and rear rest. (Yes I did cook the barrel in about 1500 rounds. But it was fun.) Guess I should have been using moly??

 

[mike in co]

To clarify.....it is the 308 AR rifle and 155 Lapua moly bullets that is the task and question at hand and the reason for posting this thread. My .224 bore bolt action rifle shoots tight and fine with naked 75Amax bullets fine. I only mentioned the 75Amax in case I find myself having to choose between purchasing the 75Amax in moly or no-moly in the future. Distributor inventories have been tight everywhere, and sometimes moly bulets are all that a dealer has available.

Yes, I agree with you that it's "ashame" that I can't get bettere then 1" accuracy so far with a $3,000 rifle. I'm still working on it. But I thought I would take this moment to show you what I'm dealing with:

Do you know what it's like trying to steady that collapsible stock on a leather rabbit eared bag? (or any bag!)

There's probably only so much I can expect out of this style rifle with a 2.5 pound barrel, collapsible stock, and quick detachable scope . I think that I'm still learning and finding out about how to hold that rifle. My bolt actions give me 2's and 3's 5 shot groups, but I also don't have to hold them the same tight way to control sliding bolts and springs.....as well as the lack of consistant follow through after each shot. I also refuse to load the cartridges at a longer length then the magazine. So....under these conditions and worthwhile sacrifices, I'll be happy to have a rifle that can consistantly shoot 1". I'll be tickled if I can get it down to 3/4" .

Such is the price I suppose to have a rifle that "does it all". It will hold 20 rounds of fast fire, can fire a high energy round out to 800 yards, or with the scope quickly pulled off, it can deliver close quarters shooting with the back sights instantly flipped up.

As mentioned in my post #21, I know this kind of rifle is not something that most guys here can appreciate, but the issue of attaining the best accuracy possible and what kind of bullets may be used to do so, is a common ground I share with you guys.







EDIT: Oh....to answer your question....It's a 6X-24X Elite 4200, and a 1-10 twist barrel.

OK....replace the bbl......
get it recrowned at least.
get a palma chembered krieger 308 win....
something is not right.

my bone stock armalite ar10t shoots 1/2 moa with a small group of 0.338. berger 175's moly'd by me.


do not mix moly /non moly and expect consistancy.
do not use a metal brush in a moly bbl.....
let chemicals do the cleaning for you.
remove carbon first with a carbon remover, and them patches to check/remove copper.

mike in co

 

[mike in co]

I was told the same but none of my moly barrels lasted any longer than the ones I didn't run moly in. In fact, had one that seemed to burn out quicker than it should have.

Since the vast majority of heat generated in a barrel comes from expanding gases rather than the friction of the bullet on the barrel, and the temperatures of the gases far exceed the temps of friction, I don't see where moly could possibly prevent any measurable barrel wear. A coating on a bullet isn't going reduce the flame temperature of the gases..............In fact, since you usually have to increase the powder charge to regain a desired velocity with moly, you would actually be increasing the volume of gas and it's effects!

i agree that no significant bbl life should be expected with moly, but there is also no INCREASE in pressure. the added powder is to restore velocity of the naked load, not to increase above it. the moly bullet appears to generate less start pressure, and we add powder to get back to that point, not beyond.

your buddy
mike

 

[J. Valentine]

A friend of mine was reading this thread about moly and sent me an email with an interesting analogy of moly. He said that moly and cleaning were a lot like shoveling the snow off the driveway. You can go out and shovel a little bit every so often until the storm quits, or you can go out and shovel the entire storm's accumulation after it's done. You will have shoveled the same amount either way but your back will hurt only with one method and not the other!

By golly, he's right!

You can clean every 25 to 30 bare bullet rounds and have a 15 minute job, or you can use moly and clean every 100 or 200 rounds and have a two hour marathon cleaning session afterwards. The choice is up to you! How's your tennis elbow?

A 2 hour marathon is a bit of an exaggeration . I have never found it that much more time consuming than a normal good cleaning session.
Also there is many commercial coating formulars that all hide under the umbrella of the name Moly. Six people can be using six differnt commercialy coated bullets and all be talking about a slightly different substance some of which have little or even no MOs2 in them.

If you coat your own with Pure MOs2 at least you know what is on the bullet and anything you observe is relevant to a known substance.

 

[J. Valentine]

I was told the same but none of my moly barrels lasted any longer than the ones I didn't run moly in. In fact, had one that seemed to burn out quicker than it should have.

Since the vast majority of heat generated in a barrel comes from expanding gases rather than the friction of the bullet on the barrel, and the temperatures of the gases far exceed the temps of friction, I don't see where moly could possibly prevent any measurable barrel wear. A coating on a bullet isn't going reduce the flame temperature of the gases..............In fact, since you usually have to increase the powder charge to regain a desired velocity with moly, you would actually be increasing the volume of gas and it's effects!

How long a barrel lasts is governed by so many factors .
If you have been using commercial coated bullets they may have a useless coating that is more like a black paint than a true pure MoS2 coating properly applied.
Hot loads will still erode the throat even with moly .
However I have seen some of my barrels last longer than previous barrels with moly. It is hard to quantify as the average shooter does not use enough barrels to get a good handle on it and all of a sudden a realy crook barrel comes along and screws up the whole data set.
I agree that barrel life is not the consideration to deciding to use it.

 

[goodgrouper]

i agree that no significant bbl life should be expected with moly, but there is also no INCREASE in pressure. the added powder is to restore velocity of the naked load, not to increase above it. the moly bullet appears to generate less start pressure, and we add powder to get back to that point, not beyond.

your buddy
mike

You're right. There is no increase in pressure. There is actually a decrease in pressure which is what requires you to up the charge to get back to the previous pressure point or node. For instance, if your gun likes 50 grains of powder with bare bullets, you will need to go to 51 or 52 grains with moly bullets to get back to that node. Since matter cannot be destroyed only changed into another state, if you put 52 grains of powder in your case, it will transform into 52 grains of gas and that is 2 grains more gas that you are burning down the bore when using moly. And that increase in gas and the resulting temperatures is going to be a far greater factor in the life of the barrel than the slight friction coefficient reductions moly gives. Clear as mud right?

 

[mike in co]

You're right. There is no increase in pressure. There is actually a decrease in pressure which is what requires you to up the charge to get back to the previous pressure point or node. For instance, if your gun likes 50 grains of powder with bare bullets, you will need to go to 51 or 52 grains with moly bullets to get back to that node. Since matter cannot be destroyed only changed into another state, if you put 52 grains of powder in your case, it will transform into 52 grains of gas and that is 2 grains more gas that you are burning down the bore when using moly. And that increase in gas and the resulting temperatures is going to be a far greater factor in the life of the barrel than the slight friction coefficient reductions moly gives. Clear as mud right?

no
its a time/volume event

the moly bullet moves further, quicker than a naked bullet. this produces a larger volume behind the bullet in a short period of time. the larger volume with more powder produces the same end results as a naked , less powder and slower movement(less volume).

clearer than mud or still murky

mike in co

 

[goodgrouper]

no
its a time/volume event

the moly bullet moves further, quicker than a naked bullet. this produces a larger volume behind the bullet in a short period of time. the larger volume with more powder produces the same end results as a naked , less powder and slower movement(less volume).

clearer than mud or still murky

mike in co

So you're saying that because the moly bullet is farther down the barrel in time the added space negates the fact that there is 2 grains more powder (the solid) turning into gas? Matter is matter. It can't be negated. It is always there in one state or another.