I've read that unless you have very smooth rifling
that moly coated bullets either don't work as well, or that the effect of the coating will be useless. Is this true?
skinner

To moly or not to moly is that the question?
Ask 100 shooters, and get 100 different opinions. If the person you ask is selling moly, it doesn't matter, if the person you ask is not a moly lover of course it does. I have customers that won't shoot a "naked" bullet, and I have ones that will only shoot "naked" bullets. I personally cannot tell the difference. I should add however that I am not one to follow the latest "barrel life extender" fad. I personally LIKE it when barrels are worn out-means more work for ME!

www.duanesguns.com

Not a fan of Moly and do not use the stuff. Why you ask, the main reason is it forces me to use more powder per round. More powder per round means faster throat errosion, period. It has often been written that Moly will increase barrel life, no one can prove it does to me. Also the Cryo treatment to barrels is also supposed to extend barrel life.

I can say my cryo treated barrel did clean much faster and easier than before the freeze treatment. It did not last any longer or shoot any tighter groups.

It would seem to me with all these statements made by Moly users and Cryo treated barrels that premium SS barrels accuracy would never go south of the border but they do??? My question is, what good is Moly and Cryo treating a barrel??? In my view moly and cryo treated barrels is just one more added cost that produces no posotive results
except in the shooters mind who are sold on both methods. If Cryo and moly were the magic potion they are given so much press by so few no barrel would ever be shot out in 10,000 rounds. We all know that is not the case and over half of all the barrel makers would be out of business in less than a year.

You have hit on a real touchy subject here. As mentioned by others, you can get LOTS of different opinions about moly coating.

In regard to the use in a barrel that is not that smooth, all I can tell you is my own experience.

I purchased a used Remington 700 VS rifle chambered in 22-250 and had a strange time getting it to shoot.
When pristine clean, it would shoot little tiny groups of 0.3 to 0.4 inches. But as soon as it got a little dirty, like 15-20 shots, the groups went to over an inch. (sometimew WAY over)

I tried all kinds of tricks and just was not happy with it. I shoot ground squirrels here in CA and prairie dogs in South Dakota and Wyoming. A gun which would not shoot after 20 rounds was useless!

The bore is less than smooth, in fact out close to the muzzle there are some obvious scratches in the bore. It looks like someone put a bore sighter in the muzzle and turned it till they scratched the bore. (I don't know, its used)

I tried all sorts of things, but in desperation, tried using moly coated bullets. I did several tests and found that so long as I use moly bullets this gun will stay around a half inch for 60 or 70 shots. Now that is more like it!!!

I now shoot nothing but moly coated bullets in this rifle and am perfectly happy with it.

In fact, I am currently shooting moly coated bullets in another rifle chambered for 22-250 Ackley Improved. After around 4500 rounds, this bore is not that smooth any more, either. But shooting moly coated bullets improved the groups on this one as well.

Just my experiences; as my gunsmith says, moly sometimes solves problems, but may not be necessary in all cases. He uses it to get more velocity out of a 7mmBR rifle in order to get more knock down on rams in silhouette competition.

R F

So it sounds like you need to try it and see how well it works in you gun.
My favorite load might not be what shoots best in your gun or the other way around sort of thing.

Snake oil, just one more variable to go wrong. If it worked the Army Marksmanship Unit and All the Palma shooters would be using it. Alot of it gets scrapped off seating the bullet.

If there it is just another thing that can go wrong then how come David Tubb still uses it?

How come theres still guys high up in the benchrest game that swear by it?

Yes it works very well in a rough bore - I have it in my Savage .223 and clean every 100 or so rounds with a couple patches of a bore mop and get groups under quarter inch extremely often with the right powder, otherwise having ANY group go above an inch is a rare occasion.

You just have to know what your doing and be sure to do it right.

Main thing is to first get all the copper out of the bore you possibly can. This is why mollying a brand new gun is easier than an older one.

Then make sure your bullets are always coated good. If your real worried about the molly scraping off (not very much will if you sive corectly and use a good chamfer tool on the neck) on the neck you could just buy a neck bushing die and find the best bushing to still hold the bullet.

I have posted this several times here on AR regarding the use of moly bullets....

Here are some moly basics:

I have shot molybdenum disulfide coated bullets for over 7 years. I have used them in my LR target/varmint guns, and my hunting guns. Basically from a 6 PPC to a .450 Dakota. I was first introduced to moly when shooting bench competitions. It was supposedly the "miracle cure" for frequent cleaning and accuracy stability. Based upon numerous testimonials at the range, I started purchasing coated bullets from Walt Berger. (He was one of the first to adopt the process for factory bullets).

Since this time, I have drawn a few observations.

1. Moly works best in small to medium calibers.
2. Moly works best in high to hyper velocity cartridges.
3. Moly works best in premium barrels. Factory barrels should be properly broken in before shooting moly.
4. Moly significantly reduces bore ware.
5. Moly reduces barrel heating by reducing friction.
6. Moly helps to calm extreme barrel harmonics.
7. Moly reduces chamber pressure and generally reduces velocity.
8. You will generally increase powder charge weight with moly.
9. Moly can allow for greater velocity while maintaining safe chamber pressure.
10. A chronograph, in conjunction with traditional pressure indications, should be used to safely work your loads back to a safe desired velocity. Don't rely solely on pressure indications.
11. Using Moly Bore Prep is advisable on new/clean barrels.
12. Always start with a perfectly clean barrel - no copper traces at all.
13. Never shoot moly over copper.
14. It is OK to shoot copper over moly, but the copper must be removed before shooting moly again.
15. It takes 20 to 30 rounds to fully burnish the moly into a new barrel.
16. You should shoot 1 and clean till 20 to ensure no copper is trapped below the moly.
17. You should clean the barrel after EACH shooting session and use a corrosion preventative for storage.
18. Butch's Bore Shine is the best general bore cleaner for moly'ed barrels.
19. Kroil works well to protect barrels for storage and helps to control moly buildup.
20. A 50/50 mix of Kroil and Shooters Choice works well for general cleaning.
21. Sweets and CR-10 will strip moly from the bore. (Not sure about the New Wipe Out product).
22. Every 100 to 200 rounds you must clean with JB Bore Paste & Sweets (or BBB) to remove throat fouling & moly buildup.
23. Once clean you must re-burnish the barrel - 1 shot clean till 20.
24. Moly fouling builds up most quickly in the chamber throat area. Should be inspected often.
25. Moly will not turn a crappy factory barrel into a sub MOA bench wonder.
26. For competition and varmint shooters it saves a lot of cleaning time. The number of shots between cleaning increases by a factor or 10 times or better before accuracy suffers.
27. Laboratory grade moly is inert and it will not break down and form some mysterious acid, nor will it attract moisture. Millions of rounds and thousands of competition shooters have proven it to be safe. No proof to the contrary has ever been submitted.
28. There is no magic or voodoo behind moly. Sometimes it works and sometimes in identical guns it won�t.
29. Factory coated bullets are the quickest way to obtain moly bullets. Moly sprays do not work as well as the shot peening and wax method - long and messy. Berger, Nosler, Sierra, and many other manufacturers offer moly�ed bullets for any target/hunting application. There are many professional coating folks who will coat any bullet for you.

Along with several fellow shooters at the club, I invested in a Hawkeye bore scope equipped with the light kit ($1,300 divided by 6 took the sting out of the cost!). I scope all my hunting rifles once a year and every few months on my high volume varmint and target guns. I monitor throat erosion, fouling, and barrel wear. I can report that moly does reduce barrel wear and has not damaged any gun that I have inspected. There were reports (range gossip) several years ago about ring stress fractures from shooting moly - I have never seen a picture of actual stress damage and I don't believe this exists.

I have burnished ALL my new barrels with Moly Bore Prep after a general break in process - even if I do not intend on shooting moly coated bullets in the gun. I am not too anal about breaking in new barrels since I mostly shoot premium barrels. However, I use Moly Bore Prep to help embed moly into the smallest imperfections within the bore. If nothing else, it makes cleaning easier.

I have seen quite a few guns that did not respond to molybdenum disulfide coated bullets. Most of my larger bore guns from .338 and up did not seem to like moly. I have worked moly loads on several .338s and .416s with less than impressive accuracy results. However, on my 6mm, .25, 6.5mm & .30 caliber cartridges, moly has worked wonders. I have found a few guns that did not like moly.

The use of moly is more of a hit-or-miss benefit in factory barrels. I have attempted to force several factory guns to shoot moly with poor results. I attribute this to rough barrels, poor harmonics, and stressed steel. One gun shot moly significantly better after being cryoed treated. Harmonics and barrel stress must play a factor.

In my opinion, moly is worth the try in small to medium bores. Make sure you start with an absolutely squeaky clean barrel. I use a little JB followed by a round of Sweets to ensure I am down to clean metal. Use a bore prep and properly burnish the barrel. Only after 30 to 50 rounds will you be able to tell if your gun is going to shoot moly well. It will take some load development work to maximize the benefits of moly. Using moly is no short cut. While you can stretch your aggressive cleaning cycles, it takes a lot of time to work your loads and burnish your barrel.

You must make a concerted effort to effectively use moly. Shooting 5 or 10 rounds will tell you nothing. If you do not start with a clean barrel and burnish the moly properly you will not find satisfactory results. Accordingly, most folks just don�t want to mess with it - I don�t blame them one bit.

[ 08-10-2002, 05:27: Message edited by: Zero Drift ]

Good Post ZD. One other thing I and others have found is that with moly coated bullets and barrel my first shot (cold barrel zero) is more often closer to or within the rest of the string/group. This is especailly true with a "clean" barrel.
for more reading on the subject go here:
http://www.jarheadtop.com/# and follow the link to chapter 4.
Wipe out will remove moly but not in one application. I took me one overnight and two ten minute applications to get it out of a 24" 300WSM tube.
Dave

Thanks Zero Drift! My oft-posted findings mirror yours to a large degree, and you saved me (and the board) from another of my diatribes. Good show!

I've still never encountered the moly buildup or waxy yellow buildup, for that matter in my barrels. Maybe it's because I just can't bear to leave them sit uncleaned and scrub it all out, I dunno. Neither do I have a borescope.

Oddly, it's my BAD barrels that like it best.

Redial

Thanks ZD. Very Informative

Hot Core - I would not suggest that you ignore other pressure signs at all. That is not my intended point. What I have generally found with moly is that it reduces bore friction, which reduces chamber pressures, which reduces powder burn rate, thus reduces velocity. In order to make up for lost velocity, you generally need to increase charge weights.

As you are working velocity back up, you will quickly find yourself outside of the max charge weight tables. I have found tremendous gains in velocity before I started finding pressure signs in my cases. A chronograph can alert you to the velocity increases well before you see pressure signs in your brass.

A few �experts� have suggested that the reduced friction found with moly tends to lessen pressure spikes and tends to generate a slightly more flat pressure curve. The same pressures are achieved, however at a slightly longer pressure curve (duration). This could explain some characteristics experienced with moly, however in my opinion, this is speculation....

In any event, I would not totally rely on traditional case pressure signs without the use of a chronograph when loading up with moly.

Jarhead is one sharp cookie in my book,,,The writings he's done are worth reading,especially if you shoot iron sights.I also agree with ZD 100%,,,especially on #13 Happy shooting!

Hey ZD, I agree with 99.95% of what you have said.

But, please bear with me on this, cause I'm still missing something. How do you use "Velocity" (10. A chronograph is the only safe method of working up loads.) as a "Safe Method" if you don't know what the velocity has a chance of reaching?

By the way, I didn't mean to imply "you" do not use other Pressure Detection Methods for knowing when to stop dumping in Powder. I've read enough of your posts to know better than that.

But, in your excellent first post, it reads to me as if a person can use "Velocity Alone" as knowing when to stop. And since the SAFE MAX velocity is an unknown, that just seems to be a bit misleading to me. Did I miss something?

Hot Core - I suspect we are beating our quite dead horse here, but to continue our discussion I offer the following AS AN EXAMPLE - THESE ARE NOT SAFE LOADS AND SHOULD NOT BE USED UNDER ANY CIRCUMSTANCES!!! (I need to say that for the more creative and impressionable among us)...

Let�s say we are loading for a new 6mm Remington fitted with a 26" Krieger barrel. We start with an 80gr Nosler non-coated Ballistic Tip. According to Mr. Nosler�s fifth edition, I should be getting about 3370 fps with 49gr of RL-19, and my Oehler confirms the velocity (Mr. Nosler is a genius). Knowing that this gun will be used for varmint vaporization, and that I will be shooting high volume with little cleaning time between long strings, I decide to begin shooting moly coated bullets. Without a question the only coated bullet for precision varmint whacking is the 80gr Berger Moly MEF.

So, I clean and clean with Sweets and JB to ensure that I am down to a squeaky clean barrel. I load up 50 rounds with 49gr of RL-19 topped with the Berger bullet. Off to the range to burnish my barrel. I use a little Moly Bore Prep and fire off the first shot, my Oehler says 3300fps. I push a few patches of Butch�s through the bore and remove the fouling. I again push a Moly Bore Prep patch down the tube and fire another shot. I keep doing this until I hit 20 rounds. During this time I watch my velocity trail off as the barrel is burnished with moly. At the end of 20 rounds I have lost over 150fps. I push a few patches of Butch�s through to remove powder and lose moly fouling and finish with a few patches of Kroil.

Realizing that IF I am going to bring velocity back to the 3370 number, I will need to increase my RL-19 charge weight. Starting at 50grs, I decide to work in increments of half grain loads up to 54grs, remembering that 49gr is the max published load number. I nervously set up my trusty Oehler and starting shooing my load development lots (5 shots each). I find that it takes 52grs to get my velocity back to 3370. I see no pressure signs and no bolt lift issues so I continue with increasing charge weights. Working though the load lots I find myself at 54grs netting 3510fps still with no pressure signs.

Now, consider where we are. We are WELL over max charge weights, We are WELL over max velocity rates, and we seem to be within safe max pressure estimates because we see no bulging primers, no pressure rings, no heavy bolt lift. The question is - �Are we really in the safe zone?�. Without a Oehler chamber pressure rig, we really don�t know. HOWEVER, we do know that we are pushing extreme velocities. This should give the educated shooter a moment of pause. We have gained an average of 140fps and increased charge weights by 5 grains. Something is pushing these bullets faster....... must be pressure. But why are we not seeing pressure signs? (That question is better left to the experts.)

All I know is my charge weights are achieving hyper velocities. I know this because my chronograph tells me so. IF I were solely relying on traditional pressure indications, I might be tempted to continue my load development well past the 54 gr level. I might miss a small tell-tell indication and continue right on until I suddenly, and quite unexpectedly, find my bolt and part of the action imbedded into my skull, and my right hand somewhere over there, and my left hand at my feet, which are more than six feet away from my head, which is unusual because I am only 6 feet tall, what is that bright light that I see, and where is that music coming from.... Well, you get the picture....

Use a chronograph to work up your loads to a reasonable velocity and continue to carefully watch for the traditional pressure signs....

Class dismissed

[ 08-09-2002, 20:19: Message edited by: Zero Drift ]

Hot Core - To save us both from a lot of additional posting, I altered point 10 - I figured this was easier. Please review and advise.

BTW - The Oehler Model 43 with screens, strain gages, and software is "only" $770.

[ 08-10-2002, 05:31: Message edited by: Zero Drift ]

Hello,
I just got on this forum today and was reading what Zero Drift was saying about the moly bullets and I must say that you did a fine job of explaining the advantages and disadvantages - nicely done!

I have been using moly bullets now for 4 years in all my rifles and have had no problems as of yet with them. My new Shilen Slect Match that I have on my 700 BDL "trued" action (22-250) cleans up in about 20 minutes, were as my other factory 700 in the same caliber takes about 45 minutes.

So ZD you are right about each gun will react differently using the moly bullets - trial & error!

Excellent, informative thread. Thanks ZD! Now a question or two.

You stated that as you fire the initial bunch of rounds thus fouling the barrel that the velocity was gradually reduced. This suggests to me that one "could" work up a safe load in a fouled/burnished barrel, clean the barrel and then the first few shots fired afterwards may not be safe.. Is this a correct assumption?

It also seems that you reccomend coating both the barrel and bullets, does this make it easier to get the barrel burnished and firing consistent moly loads as opposed to just using moly coated bullets?