Is barrel break-in really needed for factory guns?

When I got my first 40x years ago the test target had two 5 shot groups in the .2's and I'm sure Rem didn't clean after every shot. I've done it both ways and do agree that you can wear a barrel out cleaning. Jerry Teo is right on the custom barrels you can go over to benchrest.com and you will find some that don't do a barrel break in and they seem to win. I don't spend the time on barrel break in as I use to with my custom barrels. Good hand lapped barrel just don't need alot. I believe if more would just take the brush off after it pass the bore instead of bringing it back would cut the break in wouldn't be dragging all that dirty stuff back. On a factory barrel I'll do the one shot for five then see how it does just no hard and fast rule may go to a two shot clean then move up to 3 shot. Well good luck. I use a mix of GM top engine cleaner with about 1/4 of Kroil then use Sweet's. Been using the GM for over 20yrs now. Well food luck.
 
Guys I wasn't trolling when I started this thread, was just trying to come to some conclusions.

Brian, I'm no BR shooter or super shooter but when I have 2 rifles that were never broken-in and they shoot under 1/2 moa I tend to agree with Jerry's thinking. But then if I had broken them in, maybe the groups would have been cut down further. My 22-250 shoots the same groups up to about 60 or 70 rounds before accuracy falls off. The 308 hasn't been shot more than 40 rounds or so at a time with no loss of accuracy.
Am only trying the break-in this time as a test. Due to the previous rifles and the new one being factory I may not get any real conclusion. It'd take more than three barrels for that anyways. With a 308, I'm sure that I won't use up much of its barrel lfe. Sure am anxious to get the gun and start shooting. /ubbthreads/images/graemlins/cool.gif

BTW, Chevy's RULE! /ubbthreads/images/graemlins/wink.gif /ubbthreads/images/graemlins/grin.gif
 
My First custom barrel was a krieger. I called krieger and asked about the proper method for breaking it in. They told me that the one-shot-clean, then five-shot-clean methods and those similar were a bunch of bull. He said the barrel will get broken in after however many rounds it takes regardless, but cleaning after every shot then five shots and methods like that do not aid in the process. If a barrel settles down after 30 rounds then 30 rounds it is. He told me to shoot 10-20 rounds then clean just like I would normally and the barrel will be broken in when its broken in. I took his advise and he was right.

My gunsmith told me the same thing.

Does anyone here have info as to what would occur differently by cleaning after every shot vs. every ten?
 
I'm buying a used Tikka Varmint in .308 and I'm planning to use Dave Tubb's Final Finsh system on it even though it has 75 rounds through it already. According to Dave Tubbs as well as Chuck Hawk's websites I should get better accuracy, lower barrel pressures (due to lower friction) and longer barrel life (all things being equal) if I do. Anyone have any reason to believe otherwise?

Matt Roth (New to LR hunting)
 
Hi Matt, welcome to Long Range Hunting and thanks for joining in. /ubbthreads/images/graemlins/cool.gif
Why do you feel the need to run abrasives through the barrel after 75 rounds? Are there some issues with the rifle?
The lower barrel pressures seems to indicate that the bore diameter will be increased because of it and that bothers me a bit. I have a TC 14" 223 with a bit over-sized bore from the factory. It only shoots flat-based bullets well. It was purchased new. If you haven't shot it yet, take it the range a few times before doing anything that is irreversible.

Not knowing Dave Tubb personally, I'd have to wonder if he actually does that to every one of his rifles.
 
Skinny Shooter,

I can certainly understand how a copper jacket bullet smoothing out the (steel) throat area of a chamber does not make sense. I am not a metallurgist, but do have enough of a science education to understand what they were telling me might be happening on a molecular level. The following is the opinion of several experts in the field of metallurgy and mechanical engineering. (And if I am preaching to the choir, please forgive my blunder)

It has been well established the chambering of a barrel leaves marks or ridges if you will, that are transverse to the passage of the bullet. These ridges, especially early in the barrels life will scrape a small amount of copper from the bullet as it passes over them. Just after the bullet passes over these grooves, if we were able to take a high speed picture of them, we would see copper in the valleys of these grooves, much like what would happen if you scraped a bullet over a file. But the copper does not stay there long. As the temperature and pressure rise in the throat area (from the burning powder) the copper vaporizes and is carried down the barrel and deposited.

The very tips of the ridges are now subjected to heat that raises the temperature to the point the metal becomes relatively soft. As the burning powder scrapes across these superheated ridges it removes the very top of them. With the next round there is slightly less of a ridge present and hence less copper and steel is removed. Sharp pointed ridges with narrow bases, from a sharp reamer tend to be worn down quickly. Rounded, broad based ridges from a dull reamer wear more slowly and produce more copper fouling.

You can demonstrate this quite well with an old file. Take a torch and play it across the teeth. You can very quickly get the teeth to the melting point while the backbone remains relatively cool.

At least in my mind this explains why custom chambers made with sharp reamers take few rounds to "break in" and deposit little copper in the process. Also that (some) factory barrels may require many more rounds to "break in".

Jim

John M.,

Krieger is again recommending the 1 shot, clean. 1 shot, clean..... 5 shots, clean......etc. I guess its not "bull" anymore. LOL

Jim
 
They had that break-in method on their website when I spoke to them. The told me over the phone.

Call Jim or Frank at Krieger and see what they say now.
 
Jim, thanks for that info. I blacksmith as a part-time hobby/business and that explanation puts it into a perspective that makes sense. Never thought of it the way you put it but should have. I've experienced the same thing at the forge when taking a heat.
Heavier stock takes more time to heat up to temp, thin stock (the ridges) melts/burns/moves long before the heavier.
Now if I could get my peddinghaus hammer to fit into the chamber I could skip the break-in... /ubbthreads/images/graemlins/wink.gif
Thanks again. /ubbthreads/images/graemlins/cool.gif
 
[ QUOTE ]
They had that break-in method on their website when I spoke to them. The told me over the phone.

Call Jim or Frank at Krieger and see what they say now.

[/ QUOTE ] I don't think alot know about those ridges caused by chambering and Kriegers reason for clean for the first five is to cut down on the layering of copper. Doesn't matter if factory or custom still have those ridges. In my other post I talk about removing the brush after it's passed out the bore. Just my .02
 
I bought a 6mm barrel from Dan Lilja and it was hand lapped and had a saw cut for the point at which it could be finished at the front end. Dan told me that lapping will Bellmouth either end and the chamber end will take care of that end, the saw cut takes care of the other.The new barrel was subjected to about 20 rounds of break in and when it cleaned up quicker at the end I quit. It was a useful time as I was fireforming any way and the barrel never got overheated.
 
Waltech Jim,
Your experience speaks for itself. Excellent post! I agree wholeheartedly. I have looked at barrels with a borescope that were broke in properly compared to guns that were just "shot" and the view was staggering. It definetly makes a difference on a molecular level.
And still, none of the naysayers of barrel break-in have answered my question of why does the barrel all of a sudden get smoother and clean faster on the ??teenth shot.
 
[ QUOTE ]
I'm buying a used Tikka Varmint in .308 and I'm planning to use Dave Tubb's Final Finsh system on it even though it has 75 rounds through it already. According to Dave Tubbs as well as Chuck Hawk's websites I should get better accuracy, lower barrel pressures (due to lower friction) and longer barrel life (all things being equal) if I do. Anyone have any reason to believe otherwise?

Matt Roth (New to LR hunting)

[/ QUOTE ]

Welcome to LRH, Matt.

I dont buy every product that comes down the pipe.(Even though my wife say's I do /ubbthreads/images/graemlins/grin.gif)

But, Tubbs Final Finish is one I would like to take a harder look at.

If and when you try that system out, would you please post back here and let us know what you think of it??

I have never been an big break in guy. BUT...I did break in my VS .308 "by the book" and must say that it cleans up in a snap and is deadly accurate...sakofan..FWIW /ubbthreads/images/graemlins/confused.gif
 
Thanks for the welcome guys. I've been lurking, listening and learning a little for a few months.

To reply in part to Skinny Shooter, I've done a little reading about the Tubbs system and it appears to me that their system is different enough and more gentle than fire lapping a barrel and you tend to get a noticeable improvement in accuracy. Why would anyone want their barrel hand lapped? I suspect the reasons are similar, with the exception that it doesn't take expert "feel" to lap the barrel with the Tubb's system. The Tubb's system appears to be effective for new rifles as well as rifles with a substantial number of rounds through them. Of course, this is other people's experience. So far I haven't heard anything against using the Tubbs system either.

What I would really like to do is take a rig or two and look at the profile of the rifling and microstructure of the steel for a barrel using a more traditional break in and one using the Tubbs system. But that means I'd have to hack up the barrel, do some metallurgy prep on the samples and get a decent microscope. Anyone want to offer up a barrel or two??? /ubbthreads/images/graemlins/grin.gif

Oh well, I'm just starting to get back into shooting anything other than my bow and my mouth off. Good questions and I'll at least stick a borescope down and try to take a few amatuer pics for before and after. If I see a lot of copper I'll also note the difference in cleanup times before and after as well.

Matt
 
Just got back from a weekend deer hunt and started reading this thread.

Barrel break-in is a total crock of s**t and waste of your time. Gale McMillian hit the nail square on the head with his explanation.

I also respect Tubb's for his shooting, but fire lapping a barrel, come on folks think this process out logically. It theoretically can't do what it claims to do.

The bullet contact surface in the barrel is only so big. It's like trying to wax your entire car with just a tinny dab of wax and starting over at the exact same place each time you apply more wax to applicator. You just can't cover the entire car or even come close, but you get a nice shinny surface at the starting point.

Same thing with trying to use fire lapping compound coated bullets down your barrel. You get a nice smooth polished area and now an oversized throat area and not much polishing beyond that. Fire-lapping will open up and change your throat dimensions and maybe polish the next 2 or 3 inches of your barrel. Remember the whole bullet is coated with lapping compound, but only the bullets contact surface that is coated with compound will polish your bore. That's maybe 10 to 20% of the entire bullet depending on bullet design.

In the end with any barrel all you need is a good burnish in the barrel. You get that by shooting off rounds. I like to spend my time at the range shooting, not cleaning.

And think back, our parents and grandparents didn't do any barrel break-ins on their guns and you don't hear them tell stories of ruining their factory barrels because they didn't shoot and clean, shoot and clean.

Just my $0.02 worth.
 
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