A little off topic but a number of years ago there was a debate raging on molly bullets and barrel break in on another board. So I just looked at a number of site and here is what I found on both topics:

Shilen (faq)
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Can I use Moly coated bullets to break-in my barrel?

Some bullet and barrel makers say that the best way to break in a barrel
that is to be used with moly bullets is to break it in with moly coated
bullets. Others say to use uncoated bullets to break the barrel in, then
start using coated bullets. We hear from a tremendous amount of top-notch
shooters and gunsmiths and they all have their own opinions on this subject
(as you already know). In compiling this wealth of information, we have
come to this conclusion: There is no BEST way. Some barrels seem to
break-in very quickly with coated bullets. Some seem to take longer.
We've had shooters tell us that if a barrel didn't seem to want to really
"come-in" with coated bullets, a few uncoated bullets down the barrel
actually helped the initial break-in. Then they went back to the coated
bullets with good results. Our recommendation is to load and tune the rifle
with jacketed, uncoated bullets. Then try the moly coated ones.



How should I break-in my new Shilen barrel?

Break-in procedures are as diverse as cleaning techniques. Shilen, Inc.
introduced a break-in procedure mostly because customers seemed to think that
we should have one. By and large, we don't think breaking-in a new barrel
is a big deal. All our stainless steel barrels have been hand lapped as part
of their production, as well as any chrome moly barrel we install. Hand
lapping a barrel polishes the interior of the barrel and eliminates sharp
edges or burrs that could cause jacket deformity. This, in fact, is what you
are doing when you break-in a new barrel through firing and cleaning.
Here is our standard recommendation:

Clean after each shot for the first 5 shots. The remainder of the break-in is
to clean every 5 shots for the next 50 shots.

During this time, don't just shoot bullets down the barrel during this 50 shot
procedure. This is a great time to begin load development. Zero the scope over
the first 5 shots, and start shooting for accuracy with 5-shot groups for the
next 50 shots. Same thing applies to fire forming cases for improved or
wildcat cartridges. Just firing rounds down a barrel to form brass without any
regard to their accuracy is a mistake. It is a waste of time and barrel life.

Hart
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.... What do you recommend for barrel break-in?
We do not believe that a break in procedure is required with our barrels.
If you follow our normal cleaning procedure, outlined in this brochure you should
not have any problems with your new rifle. You always want to clean your rifle
as often as your course of fire will allow. If you have time to shoot one and
clean, that would be fine, but we personally do not feel it is necessary.
Please be sure to only use the cleaning solvents listed in our
cleaning instructions.

.... What about Moly coated bullets?
We do not recommend the use of moly bullets, as we have not seen an increase
in accuracy or barrel life from using them. We have measured moly buildup up to .0005 for
the first 2 - 3 inches in a barrel. We have not found a cleaning method that adequately
removes the moly without potential damage to the barrel. If you elect to use moly bullets,
we recommend that you contact the bullet manufacturer for details on the cleaning
method they recommend.

http://www.schuemann.com-> Moly warning
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This is the strongest warning I have seen. I do understand it is a pistol barrel
maker but they reportedin one unscientific experiment (read the report) barrel
life was cut to 5,000 rounds where it is not uncommon to see 40,000.

Lija - from the faq
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Q. What is your opinion of the use of moly coated bullets?

A. First, as described in our section on barrel break-in, we do not recommend the use of moly coated bullets for break-in. The break-in process requires the use of an uncoated jacket if it is to be successful.

Secondly, at the risk of offending those that promote the use of moly, we can't see much benefit to it for a couple of reasons. There are two basic claims made for the use of moly, reduced fouling and increased barrel life. We'll look at both of these.

We agree that bullet jacket fouling in a barrel can and will cause accuracy problems in a barrel. But for the most part, jacket fouling in a hand-lapped, match-grade barrel is minimal. For the small amount of copper fouling that does remain in most barrels, conventional cleaning methods can and will stay on top of the fouling. We recommend cleaning solutions like Shooter's Choice and/or GM Top engine cleaner mixed with Kroil oil and the limited use of Sweet's solvent. Our suggestions for cleaning can be found in the Cleaning and Break-in section.

We have examined barrels with our bore scope that have had an excessive amount of moly fouling layered with powder and jacket fouling. The only way we could remove this buildup was through relapping of the barrel. Perhaps part of this type of problem results from a mindset that says "Hey, I'm using moly now and I don't have to clean very often." So if you do elect to use moly coated bullets we recommend that you still clean as often as before.

So, the obvious question to us is, if regular cleaning is still required with moly and if a bullet/cartridge/barrel combination does not foul to any great degree without moly, what is the advantage to moly?

This leads us to the second part of our answer. Some of the promoters of moly claim an increase in barrel life. While this sounds good on the surface we must ask the question: what causes a barrel to shoot out? Barrels wear out, or no longer shoot up to their original performance levels, because of erosion to the throat area of the barrel. This erosion is caused by heat and pressure created by burning powder. As a throat lengthens, velocities fall off and accuracy can suffer too. Eventually more and more of the throat will be eroded and moved forward. Also the diameter of this eroded section will increase. We have seen take-off barrels that had fully 1/2 of the length of the rifling completely eroded.

The key to this type of erosion is that it is caused by hot powder gases under high pressures and not by friction between the bullet and the barrel. We have read a report from a military test that examined this type of barrel wear. It was found that over the course of tens of thousands of rounds the actual groove diameter of the barrel was only increased by a few ten thousandths of an inch. It is this type of wear that moly might prevent or slow down. But in this test the throat area grew progressively longer and larger in diameter from gas erosion, not friction between the bullet and barrel.

So from our point of view, moly coated bullets are not going to prevent the type of throat erosion we have described, that the type of wear caused by friction between the bullet and barrel is insignificant, and that the prevention of jacket fouling through the use of moly is marginal at best and that moly may add another type of fouling to the barrel.

There is one type of shooting that may benefit from the use of moly coated bullets, in our opinion. In an effort to find the "perfect" bullet, target shooters using the 50BMG cartridge have manufactured solid bullets that are lathe-turned from materials like brass, bronze, copper and even soft steel alloys. These bullets can cause a considerable amount of barrel wear caused by friction between the barrel and bullet. The bore and groove diameters of these barrels do increase in diameter as a direct result of this friction. And this wear is not caused by the hot powder gases that will erode a throat in more conventional barrels.

In this case it seems as though, in our testing, that coating bullets with moly will help reduce this type of barrel wear.

We realize that our opinion of moly does not go along with the wisdom and promotions of the day. But we're willing to listen to opposing views if you have one.

Post Script: In the January, 1999 issue of PRECISION SHOOTING Magazine there is an excellent article by Kevin Thomas of Sierra Bullets about his experiences with moly. I would suggest that anyone considering using moly read that article first. In summary, Kevin found almost the same results as we've outlined above. In short he found that moly had no effect on extending barrel life in their controlled accuracy testing of bullets during production. He did not see any improvement in accuracy and to the contrary even found some degradation in accuracy at times, and that moly could create its own fouling problems. Mr. Thomas found that moly did reduce jacket fouling a little but that a regular cleaning schedule was still required. Like us he wondered what if any benefit there was to using moly?

Sierra
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Speaking with on of their techs they told me in their mind the report card was still out and they were
offering moly because customers demanded it. Not necesssarily the evidence of more barrel life, etc.

Krieger
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If you speak with their techs, I get the impression they have much the same opinon as Sierra, Hart, and Shilen.

This is why I break-in ALL my centerfire barrels:

http://www.kriegerbarrels.com/Break_In_ ... wp2558.htm

http://www.riflebarrels.com/support/cen ... enance.htm

http://www.bartleinbarrels.com/BreakInCleaning.htm

http://www.pac-nor.com/care/

Please, please, please, carefully read the write-up on the Krieger site!!!! It gives the most scientific and complete reason why breaking in a barrel is needed. And if I ever hear anything about a lapped barrel in connection with a discussion on breaking in a barrel I will make a note not to pay any attention to what that person says in the future.

Now I realize that none of these sources are as authoritative as your cousin's, best friend's, former husband, who's father used to work for the best gunsmith in town but they are good enough for me!!

Trent....there's no magic in break-in..its called burnishing a surface so copper doesn't cling or foul. Copper doesn't deposit evenly and builds up if not removed..that my friend is why the cleaning....but not necessarily between every shot. A good barrel only takes 2 or 3 repetitions. Perhaps the bench boys know something considering they go through more barrels than any of us. I agree with your cleaning aversion but break-in pays off and its not that difficult. But as JIM T points out...I'll continue doing it.... then again I failed to consider that you're one of the believers in 6.5 voodoo

It's all theory at this point. Period. Otherwise we wouldn't be having this discussion.

Snake, I agree that barrels "break in" (aka burnishing imperfections). The bullets are going to to that whether you clean it or not. If a barrel is predisposed to "break in" after 25 shot it will do it whether you "shoot 1 clean 1" 25 times or if you just shoot it 25 times.

That's my theory. I can't prove it any more than you can prove yours.

Besides, I've seen you shoot… breaking in a barrel isn't gonna help that mess!

I have read about this product does it work or just a gimick? http://www.davidtubb.com/ff-kit-284-7mm-cal

workinmansteve wrote:I have read about this product does it work or just a gimick? http://www.davidtubb.com/ff-kit-284-7mm-cal

I've seen it work for a friend with a really rough and poorly shooting factory rifle (was well outside of "normal"). Personally I would only use it as a last resort and never on anything resembling a custom barrel. It's just an agressive form of lapping out a rough bore. It did work on a buddy's barrel, but that barrel couldn't have gotten any worse.

Trent...no one said shoot 1 then clean...but you have to remove the copper fouling. If you let too much of it build up it reqires more effort to remove it...clean while you burnish. By the way I've been a triple A a long time...and its tough to get good scores when i run the match and keep an eye on you so you don't hurt yourself
In regards to the 'gimmick' in the early 30's Mobil came up with a bullet lube, said it would reduce fouling. So all the Camp Perry army shooters used it...it worked but like all guys if a little works then a bunch has got to be better. All of a sudden they began blowing up actions...turns out the lube migrated into the chamber and defeated the adherence of the cases to the chamber walls...they slammed back and broke bolts and fractured actions o Careful with gizmos etc for the whole story see Hatcher's Notebook

Trent, Are you measuring pee-pees with Snake?

"It's all theory at this point. Period. Otherwise we wouldn't be having this discussion."

Apparently 4 of the top barrel makers in the world think we are beyond theory. I suspect there is not much "discussion" going on in John Krieger's head about this.

If anyone takes the time to read, and more importantly comprehend, the material at the links provided in my previous post above they will no longer be ignorant on this subject. If they ignore the advice of these 1st tier barrel makers then they, in theory, would be labled stupid.

Label me stupid. Jim, you must be pulling off the same bottle as Marv these days. Check the attitude. This is a jovial discussion.

Well written theory is still a theory. So 4 barrel makers list a break in process... must be a fact then. Guess that settles it. Let the rest of the world know about these FACTS so that everyone can stop discussing it. The other top barrel manufactures that say its a waste or at least unproven must be on the stupid bus with me. How dare I "ignore" the "facts". I guess I missed the thorough test where someone was able to take a bunch of barrels and test them one way then turn back time and test them the other way to prove once and for all that "breaking in" a barrel does anything MEASURABLE.

Stupid out.

Trent:

Not sure why you accuse me of drinking in the middle of the day? I did finish up the bottle of 2000 Chateau Leoville Poyferre (very, very, good!!) from last night for dinner but that was well past the time I posted the post that your characterize as not "jovial."

As for Marv, I have to admit he does have a different writing style but I usually can read between the lines and understand what he is trying to cummunicate. My only advice is to wear body armour to protect thin skin! He apparently does have a good track record for design and machining, how about you?

The only thing I can say is I answered the OP's question, so far you have not.

I have this nagging vision in my mind of Messrs. Bartlein, Kreiger, and Lilja on one side of the room and you and now the guy from 8514 Tactical (I could swear that guy was indicted for marrying his cousin!!!) on the other. I think you know how it turns out.

In my 55 years of life I have found in a myriad of circumstances that when making a decision you absorb as much data, advice, and experience (both yours and others) and then make the best decision you can. It has worked pretty well so far.

Cheerfully,

Jim

More experts ....

http://www.youtube.com/watch?v=mISAOX5-AE8