Objective research on Barrel Break-in procedures

Re: Objective research on Barrel Break-in procedures

What a great read this thread has been.
Information from both sides and more information from some that steer way off of the subject but all great info to know.
Thanks for this.
Re: Objective research on Barrel Break-in procedures

well these all make sence, but I do what I always do for the life of the rifle. I clean with a soft brush, then after ever three shots I use a soft pull threw like a bore snake. I do this ever time I shoot...
best regards maddawg
Re: Objective research on Barrel Break-in procedures

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: halfclue</div><div class="ubbcode-body">I am glad I took time to read this. There is so much confusing BS at ranges, gun stores, and some forums.

If you take the time to read all the posts it is the same here. I go along with the fellow that started thus thread. No formal breakin, just let your barrel tell you what it needs.
Re: Objective research on Barrel Break-in procedures

Always a nice diversion. I apologize if I don't cover exactly what OP wants, but I did want to share some stuff. Hopefully it may either help or shed some light. First, I'm a gunsmith - and I can pretty much do anything I want with my own stuff. I say that not because I mean I can wreck something and just buy another; rather, I mean that I RARELY have time to work on my own stuff, so I have to be precise, decisive, and CORRECT about what I do and how I treat my stuff - ie pay attention to "what it wants".

It's ironic (this thread) because I just cut a thread tenon for a 6.5-284 I'm building on a Krieger.....and I was actually wondering how long it would take THIS barrel to "clean". I finished one last week that "cleaned" after 3 singles and a 5 shot group...
Here's what I mean.

For the most part, I think break-in is voodoo. However, my approach in "break in" is more about what I do to make it clean easier in the future - and that is ONLY my opinion. I have zero empirical evidence to the contrary because I have always used the following routine - and I tend to stick with things that produce results I seek.

Anyway, I believe Gale McMillan once said that a custom barrel is NEVER going to shoot any better than when first fired - the logic being that the hand-lapped perfection is obviously smoothest at that moment. I agree in terms of lapping, but also believe in smoothing out tool marks. Factory barrels have a ton. Even custom jobs I do - wherein no shortcut is taken to indicate concentric to the bore, borescope before, during and after - there are GOING to be at least some striations/cross-grain structure visible around the leade. I use piloted finishers, sweat the small stuff, etc - but they are there because metal is being shaved at a 90 degree angle to the lands. However, those striations are usually gone within relatively few shots.

On customs, my process is simple - shoot one, clean to observe fouling, scope it to see if any changes happened, repeat. On a match barrel, I have never had to shoot more than 5 of the one-shot cycles (which is good because I hate doing it)before I was able to start shooting groups. I clean after group one, and if it's looking good, I'll shoot and clean for another 3-5 shot group (depending upon how it's developing). In other words - the barrel tells me when to stop playing and start shooting. I developed this routine from Krieger's recommendation, and I use their barrels almost exclusively (and disclaimer*any reputable custom barrel is great - I just like Kriegers...lol...no wars sought over barrels, here)

Factory is another critter altogether. I suggested Final Finish to a buddy who couldn't afford a barrel job on his .300 and he got really good results. Accuracy gains may not be great, but it cleans MUCH easier for him (when he cleans it...lol).I scoped it for him before and after (could tell a positive difference), and who knows how many fewer shots you can fire by using Final Finish? I certainly don't. However, I do feel like it fire-laps well. Will it reduce barrel life? I'd have to say "sure"...but to what degree?

Here's what I tell customers - if you WANT to one-shot-clean or use final finish on a factory barrel, do it! However, pick the absolute best cleaning rod/bore guide you can find, be VERY careful, and try to learn your rifle. If they are buying a custom rifle from me - they don't have to worry about because I do the initial part for them. And invariably, once it starts to "clean" - it starts to bughole.

I hope this is not too convoluted to do any good...
Good Shooting!
Re: Objective research on Barrel Break-in procedures

After reading some of the posts...I only have factory barrels and have used the 1 shot then clean repeat..etc.etc...
I'm positive that my gun will probably outshoot my skill level. Very good information everyone!


Gunny Sergeant
Re: Objective research on Barrel Break-in procedures


That was a long read.

So my rifle that's coming back from the gunsmith with a 5R rock creek barrel shouldn't have to be cleaned

that moly coating that he puts on should prevent metal to metal. but will it wear off? common sense says that it will wear off. but how fast?

how do I take care of that fine barrel after the 20 break in shots? after the break in period, when I come home, do I clean it with some solvent like bore tech eliminator? can I apply weapon shield to it and not worry that it's gonna strip the moly coating on the rifling?

I usually just run a bore snake after shooting with weapon shield on it about 5 times through the barrel and leave it until next range time. I shoot like that I as well. I leave the oil on there for my 1st shot.
Re: Objective research on Barrel Break-in procedures

Awesome write up and really helpful. Ive been searching for something like this for awhile. Now i have to decide which way to break in the new AI.
Re: Objective research on Barrel Break-in procedures

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lowlight</div><div class="ubbcode-body">I pull a bore snake through once before shooting it, incase they left some grease in the tube. But I do so dry as I don't use chemicals on my snakes. </div></div>

Why do you not use chemicals on your snakes?
Re: Objective research on Barrel Break-in procedures

Thanks for all the info. I have a new Remi 700 LTR with a Bell & Carlson stock being built up and really appreiate all the info presented. Seems I always find good stuff on the Hide.
Re: Objective research on Barrel Break-in procedures

may i add in two things about so-called break in , ok its a roughly made barrel -ok now clean it up -great ! wrong ,bad Q/C !better tooling and less troubles at the manufacturing of the barrel and installing of it ..the other factor is the action tuning /bedding settling is more the point so all works together - all finds home right ..


CPT USA (ret)
Re: Objective research on Barrel Break-in procedures

SO glad I took the time to read the original post and several hands full of replies.

I've had this sneaking suspicion myself for years that the tried and true methods for barrel break in were only so much superstitious ritual.

Had a friend shoot a Rem 700 PSS to death after something like 5000 rounds (plus) and he never ran a patch through it. Ever. He did have a friend clean the trigger/bolt for him ONCE because the carbon and crap froze the trigger solid. That gun could SHOOT, as did Bill. LIke cantaloupes at 970 yard accuracy.

I generally just run a patch with some CLP or Hoppes #9 through my guns after the range and put 'em away.

I'm not shooting bench rest for a cloverleaf wallpaper collection.

This was reassuring.

Re: Objective research on Barrel Break-in procedures

wow......I never believed there was anything to gain by a "proceedure" on a new barrel. which has been claimed on many boards as a fallacy,like here.

I always clean my "factory type" rifles and the barrels after I shoot them, only because thats the way I grew up and I like doing it.plus I like to see whats going on. I like keeping a very fine thin film of oil on them,myself.
Re: Objective research on Barrel Break-in procedures

Thaknyou for the write up. It has helped me. I am just starting out in long range. This site is very helpful.


Gunny Sergeant
Re: Objective research on Barrel Break-in procedures

I always start asking the cleaning voodoo question every time I change a barrel or get a new gun. I ask myself what do I do this time. Overall I have done about a half dozen different formulas and came out with the same result, 1/2 MOA guns with and without break in.


Bubble Head
Re: Objective research on Barrel Break-in procedures

good read, but the break in procedure worked fine for me ... could definitely see the point where the amount of fouling went way down.

i have another rifle, with which i ignored the break in procedure. shoots just fine.

guess i'm fine either way, but it is a real pain bringing all that cleaning gear to the range (esp. when it's windy).
Re: Objective research on Barrel Break-in procedures

Wow that took a long time to read... not sure I gained much.

As a chemist who uses scientific method very frequently in research I need to say something to the people looking for "the facts" on this topic. "Facts" would suggest a real study. One that I am sure is not realistically possible.

Since all barrels are different you cant test one and done. The more you test the better the results. When I run samples and test im talking about 50+ per individual variant. And to many peers thats nowhere close to enough... Anyways that means to get this kind of data we are looking at 100 rifles to test for each type of barrel. Half for - shoot clean shoot clean etc. Half for just shooting.

If thats not enough then also look at how you report findings. To have supporting information to have "facts" we need units. Something to judge it by (units of measurement). How would you do this? Accuracy is the easiest by going by group size at distance but still thats riddled with error, shooters error, environmental error, cleaning inconsistencies, inconstant ammo, etc etc... There is way to much inconsistencies. Then how do you measure fouling? guessing by how it looks? removing all copper and measuring it somehow? Still tons of error.

If you ask me or any other scientist (which I am sure no one did) there is no reasonable way to test and have valuable data, without massive resources.

That being said... I say break it in by shooting and cleaning. If your that worried about it then why not? If you do and it turns out you didnt need to then all you did was waste your time and no harm done (as long as you didnt damage during cleaning with bad technique). Eventually you will stop this shoot/clean sequence and just shoot alot before cleaning which is exactly what you would be doing if you did not "break it in."

So why not do it? if it does help then it helped. If it doesnt then it didnt and there was no harm done. But I doubt you will ever really know which it was.

Just my .02 that no one asked for! Now stop reading and go shoot!
Re: Objective research on Barrel Break-in procedures


You bring up many valid points. This is one of those topics which there are many variables and moving parts. At the time Stan shared some studies they performed while he was working at Raytheon. With his info as well all of the other data, barrels and interviews I did the conclusions were the same. I feel I gave a solid basis for my conclusions; it’s better than a bunch of hearsay, opinions and most of the nonsense I’ve read over the years, though maybe not thorough or detailed enough for some. I appreciate your insight and feedback all great points and welcome to the hide!
Re: Objective research on Barrel Break-in procedures


I see where your coming from and sure any data, with flaws or not, is still better than baseless opinion. While I find your results enough for a solid hypothesis of whats going on, just not enough for a solid conclusion. But then again Im not sure there can be anything completely conclusive. I do think you have shown enough for people to make a more educated decision when it comes to breaking in their barrel, which I guess is the whole point! When it comes down to it you just want to feel like you did the right thing and can be confident in your rifle.

I hate to say I can help if you wanted it given that I am on this forum to learn for you guys but if you need help developing a test method to be "more accurate or precise" thats something I can help with.

Keep up the good work.


Gunny Sergeant
Re: Objective research on Barrel Break-in procedures

Just putting this out there.

In one of the clips from the new MagPul series Hodnett says that he has had rifles (with good after market barrels) hold 1/2 moa accuracy for 8,000 rounds by only cleaning the carbon out of the barrel after each session. After 8,000 rounds he cleaned the copper and it shot over 2 moa for the first 43 rounds then returned to 1/2 moa. He said its the carbon that pits a barrel and that unless you have a barrel that builds up excessive copper quickly to leave the copper in it. Claimed he has done it with 338 LM and 308 and some have over 11,000 rounds through them.

I can't say that that info is accurate, I wasn't a witness and I did not do the test. I hope it is because I'm going to try it, at least until/if I see a major fall off in accuracy in my Mike Rock barrel.

I do know if I made my living selling barrels or copper solvent and brushes that I wouldn't want it to be mainstream info though haha.


HMFIC of this Shit
Staff member
Re: Objective research on Barrel Break-in procedures

It's been talked about a length, I guess it takes a DVD to sink in...

SHR #50 went over 15,000 maintaining 1/2 MOA accurate with less than a cleaning per 1000 rounds, and all that for just copper.

The original Harbinger went 12,000 rounds with the same and stayed around 3/4 MOA at the end, it was only cleaned for carbon and barely for carbon.

in fact 90% of my rifles don't get any cleaning but for carbon, and the only one that exhibits any copper fouling is a 6.5CM. So in that case it gets a copper treatment.

The rifle will dictate and better barrels yield better results.


Gunny Sergeant
Re: Objective research on Barrel Break-in procedures

I'm still kinda new to long range and to this site LL so almost everything I saw on the DVD series was new to me. Just like you guys said, the Caylan disc was real good. I did learn some from the other discs but I don't have a filter as to what was good, what was not and what was half explained/taught right.



Gunny Sergeant
Re: Objective research on Barrel Break-in procedures

I chose to do the barrel break in. I avoid moly bullets because of all the stories I have heard about them. My barrel was a factory remington barrel and not a match grade one that has been hand lapped.

I did not have a bore scope but my concept was simple. I did shoot and clean it as well as used JB bore paste, bright, and Flitz in my barrel. My thoughts in this were that:

A: A barrel that is clean and has less resistance will give better velocities that are more consistent.

B: A clean barrel that has a slick polished bore has less chance of fouling because it is hard for the fouling to latch onto. It is like a waxed car, you slide right off it.

C: A polished bore that fouls less will hold accuracy longer between cleans. I have seen some guys lose accuracy after 10 rounds down the tube. Now I am not talking about match grade barrels. Factory hunting barrels.

I may be completely wrong. I have less research in this department than the majority of everyone on this forum. I am just saying these are my thoughts. It may just be luck but my factory remington 700 5-R is shooting consistently under 1/4 moa and I am not a perfect shooter. Either I got a fluke of gun or my theory worked.
Re: Objective research on Barrel Break-in procedures

Great info here. Makes me wonder how many great barrels have been damaged by too much cleaning and dicarded because the owner thought he "shot" it out.
Re: Objective research on Barrel Break-in procedures

This has long been a topic of intrest for me I thank you for
your indepth post on the subject its great to hear from
the manufactured and seasoned vets on how to get the most from your valued rifles.
Re: Objective research on Barrel Break-in procedures

Awsome awsome post thank you very much for your knowledge and expertise. Ive heard alot as Im sure others have aswell searching the internet hearing all sorts of hogwash regarding break in procedures. I will be refering anyone who asks or thinks barrel break is necessary to this thread and Im gonna bookmark it myself.
Re: Objective research on Barrel Break-in procedures

I have never understood break in. It breaks down to thinking that the copper jacket of a bullet will somehow wear down chrome moly (or stainless) steel's imperfections those first few rounds...but than NOT wear the barrel the rest of the time...? Hokum!

But it gave me GREAT peace of mind reading about lowlight's unscientific testing of the twin TRGs.

Now if only my 22-250 would last 10k+ rounds. THAT would be awesome!
Re: Objective research on Barrel Break-in procedures

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Jeff in TX</div><div class="ubbcode-body">He uses two products from Sentry Solutions. One product is called Smooth Coat, which is an alcohol and moly based product. He applies wet patches of Smooth Coat until the bore is good and saturated and lets it sit until the alcohol evaporates. The barrel now has loose moly in it. Next he uses a second product for Sentry Solutions product called BP-2000, which is a very fine moly powder. Applied to a patch wrapped around a bore brush, he makes a hundred passes through the barrel very rapidly before having to rest. He repeats this process with fresh patches containing the moly powder a few more times. What he is doing is burnishing the barrel surface with moly and filling in any fine micro lines left by the hand lapping. He then uses a couple of clean patches to knock out any remaining moly left in the bore.

Would this work with HBN if I plan on shooting hbn coated bullets?

Suspend hbn in alcohol and us in place of Smooth Kote and dry hbn in place of BP-2000.
Re: Objective research on Barrel Break-in procedures

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Cory Lee</div><div class="ubbcode-body">Would this work with HBN if I plan on shooting hbn coated bullets?

Suspend hbn in alcohol and us in place of Smooth Kote and dry hbn in place of BP-2000. </div></div>


Not sure what HBN is, having said that I think Mike Rock's point here is just to make sure your barrel starts out and maintains a good burnish. So if I speculate I'd say adding hbn in replace of Smooth Kote would do the trick.

Hope it helps
Re: Objective research on Barrel Break-in procedures

For the initial break in the idea is to remove burs etc that cause copper fouling. Sometimes for various reasons one or all of the lands pick up copper. Breaking in a barrel isn't required. Even in the field manuals they say given the opportunity you should follow break in but if operational tempo requires putting the unit into service before breakin it's not forbidden or anything. I settled on a middle ground, Shoot 5 clean/ so on. But the cleaning is mainly when I see copper fouling or start throwing odd rounds. Each barrel is different due to cut/ button method, barrel twist, caliber etc. ex most 308's have long barrel life and it really doesn't seem to matter to much. Also cleaning the barrel with solvents like sweets 7.62 can do more damage than just shooting can do unless you end up with something as hard, or harder than stainless going through the barrel. (hence why you don't use stainless bore brushes, the brass/ bronze brushes are softer than the ss.
Re: Objective research on Barrel Break-in procedures

I've tried it both ways. I know guys who swear by "breaking in a barrel" and guys who swear it's BS. I guess Ill find out down the road which one goes first.

Greg Langelius *

Resident Elder Fart
Re: Objective research on Barrel Break-in procedures

I've been initializing new barrels for probably close to two decades by now. Over that time, various approaches have come into vogue and then been supplanted by others.

Originally; I didn't know any better and just unpacked them and shot them. Never recognized any issues, but again, I didn't know any better. Nowadays, I'd clean the rifle thoroughly before shooting it. The first time I tried that, I got out an amazing amount for grit and crud. I'll never take a chance on running bullets through that kind of junk again.

When the shoot/clean process came to my attention, I figured it was a great idea and followed it religiously. When abrasives were incorporated within that, I even developed my own technique that involved coating bullets from loaded ammo with mild, non-imbedding abrasive, like Rem Clean or JB Compound.

I don't think I did any harm, and I chose my technique/materials so as to limit the potential for harm. I wrote it up here, and I sure lots of folks followed my lead.

I haven't done it lately, but I still think it has a place in intializing barrels where rough bores are involved. Viewpoints vary on whether a rough bore equates to diminished accuracy. I don't know whether either argument is better but I do believe a rough bore encourages copper fouling and that copper fouling degrades accuracy once it reaches a certain level. Hence, honing a bore can postpone accuracy degradation due to cumulative copper fouling.

Another argument favors removing initial tooling marks associated with the throating proces of barrel making. I think it's a valid argument. I think that judicious use of abrasive honing techniques can hasten a barrels's stabilization, to where the copper fuoling rate steadies down to more or less a constant rate. I personally believe that until this status is achieved, load development is a waste of time, good components, and bore life.

Basically, we are talking about wear rates that bring the bore and throat from the newly cut condition to a worn and constant condition. Whether this is down overtly through firepolishing, or by hand lapping/honing, the net effects are quite similar, or at least can be when done judiciously.

But, this accelerated wear rate can be skipped and substituted with regular wear from customary shooting followed by post shooting session cleaning, and we'll essentially arrive at the same status, differing only in the number of shots accumulated in the process.

Up to this point we're mainly just doing the same thing over shorter or longer lengths of time and numbers of shots.

There is, however, another factor that I don't see being discussed as part of this argument.

Barrel life isn't determined by barrel wear or friction. It is determined by the number and degree of heat and pressure cycles the barrel's throat experiences.

For the sake of argument, a process which stabilizes the barrel earlier in the sequence of heat and pressure cycles <span style="font-style: italic">should</span> permit a longer sequence of 'good' shots within the allotted/fixed total number of cycles the barrel can sustain.

By this argument, a quicker break-in process <span style="font-style: italic">should</span> allow more lifetime where the barrel's performance is consistent, before the heat and pressure cycles accumulate to end the barrel's usefulness.

If I were to lend a contribution to this argument, that would be it.

There was also a question about a formula for extended bore life. Logically, my answer would be 'anything that decreases the punishment the throat is subjected to by heat and pressure'. In essence, use tamer loads. It's my personal belief that hotloading and bore life expectancy are diametrically opposed.

Very simply, if the chambering you're using does not generate the performance you seek while running moderate pressures; then that chambering is inadequate and needs to be replaced by one with more case capacity. Hotloading (IMHO) is just a matter of trying to achieve the improbable while simultaneously opening some cans of worms that nobody really needs opened.



Gunny Sergeant
Re: Objective research on Barrel Break-in procedures

I find the anecdotal stories and explanations on either side of the barrel break in interesting, but not true evidence of whether break in works or not. A truly "scientific" study would be very expensive, and I think that is a primary reason that it has not been done. The following are some of the more siginificant reasons a true "study" that produces scientific evidence would be expensive.

1. You would need at least two rifles, prepared in as "exactly" the same way as possible. You would also need two barrels mounted onto these actions prepared in the same manner.
2. The test would require a great deal of ammunition.
3. Rifles would need to be cleaned by one person, and tested by another person who did not know which rifles had received "break in" and which had not. This would be the only way to avoid as much of the human influence as possible.
4. Targets would have to be evaluated by someone who did not know which targets were fired by which rifle so there could not be a tendency to favor a close call to one rifle or the other.

This kind of blind testing is both expensive, and very time consuming. As most custom barrel makers are already short on time and can barely make enough barrels to keep up with demand, they have no real need to do any testing. In short they don't need to convince anyone either way, because they have more demand for their product than they have time to make barrels.

I think these are the primary reasons that no one has done any real "scientific" testing on the break in issue. The people who make barrels don't feel the need to convince anyone either for or against break in. They already sell everything they can make, so they have nothing to gain by doing the testing.


Gunny Sergeant
Re: Objective research on Barrel Break-in procedures

Just to throw this out there,

Took my brand new .308 with a 20 inch Obermyer barrel out today. Decided not to do a break in. Fired 65 rounds through it. Cleaned it when I got home just to check for copper fouling. Obviously first wet patch came out sloppy black. Dry patched it twice and it started coming out clean.

Ran a patch with some copper solvent and let it sit for a few minutes. Dry patched and absolutely no blue on the patch, not the wet one or the dry one.

Barrel cleans easy and quick with no cooper fouling at all.

Break in would have been pointless.
Re: Objective research on Barrel Break-in procedures

I go along with the thought process that if the metal of the barrel is polished to an extremely smooth finish, it's less likely that copper has anything to latch onto to foul the barrel.

I've been doing something with my last few rifles that seems to work really well, doesn't waste ammo, is easy to do and doesn't cost hardly anything.

My equipment for the project is a cleaning rod, bore guide, four of the appropriate caliber rifle BORE mops and some Flitz.

I start with a good, thorough, complete cleaning to insure there's no copper to cover up any of the barrels surface to be "polished". I run a couple of patches worth of 91% rubbing alcohol down the bore to insure there's no oil left in the bore before I begin but I don't do this unless I'm all set up and ready to begin applying the Flitz immediately thereafter.

I slather up the bore mop with a load of Flitz and run it back and forth about 15-20 times. The bore mop is BLACK when I remove it. I push out the excess "dirty" Flitz with some clean patches, put on a new bore mop, load it up with clean Flitz and hit it again. By the time I get to the fourth bore mop it hardly changes color at all. I don't have a borescope but I think it's safe to assume that if the boremops aren't getting nearly as black at the end of the process, some "finishing" of the barrel has taken place.

The barrel looks like a mirror when I'm finished and cleaning is a snap. After a "treatment" I just shot my new Savage model 12 lefthand varmint .223 to check on what kind of factory ammo it likes. I fired 60 rounds and a spray of M-Pro7 gun cleaner to clean out the carbon and then a patch saturated with M-Pro7 copper remover followed by a couple of passes with a bore brush, one more pass with the copper remover, some clean patches and the barrel was clean.

Fired 17 groups of 3 rounds of factory ammo to see what ammo it likes-5 groups less than .5 MOA, 2 less than .54 MOA, 1 less .7 MOA and ALL of them less than 1.15 inches. Best group was .304.

It may not do beans but it's easy and cleaning is a snap. Heck, I jus enjoy doing it anyway!!!