Separate names with a comma.
Discussion in 'Competition Shooting' started by MrBombastic, Oct 5, 2007.
Is it ever necessary to "break in your barrel" on a new gun?
Does anyone know how to do this?
Yes, you should break in a new barrel. Usually the manufacturer of the rifle will tell you, or you can check several barrel makers websites.
Loosely it follows something like this... One round, clean, then another for the first 10 rounds. Then 2 rounds, clean, for the next 10 rounds. Then 3 and clean for the next 20 rounds. and so forth out to about 200 rounds.
If it is chrome lined, then it is abbreviated.
If you break in your new barrel it will make it easier to clean for one thing. If you make no effort to break it in it will everntiall smooth itself out on it own, but you will have a harder time cleaning it.
There are about as many ways to break in a barrel as the are people to tell you how. Min. I would fire at least 5 shot cleaning after each one with powder soulvant and a copper soulvant. If your not getting any copper, blue on the patches, you need not use the copper soulvant every cleaning. Then shoot 5 shots and clean. You should be able to feel the difference in the way the patch slides through the barrel. If it keeps getting easier you can keep doing it or just keep cleaning it after every hunt or trip to the range. It also helps to use JB bors past or a similar product when breaking in a barrel.
I'm sure I'll start something with this, but a high quality aftermarket bore needs no break in. It is Match ready from the manufacturer. Thread, chamber and crown it, then after a couple fouling shots to foul the bore, it is ready to shoot for score. That is part of what hand lapping a bore as the final step in the manufacture of a barrel will do.
A non-hand lapped bore should be broken in, with the number of rounds per string between cleaning, and the number of strings shot to be determined by the condition of the bore after slugging it and measuring the slugs, and visual inspection of every inch of the bore with a borescope. A non-hand lapped bore will have all kinds of machining flaws that will be readily visible to the eye when the bore is scoped. And when you slug and measure a bore like this, it is a very rare bird when you find one with consistent bore dimensions, and - heaven forbid! - the bore being perfectly round (versus egg shaped), and the bore dimensions (bore diameter and groove depth) being within 0.0005" of what they should be. I won't even get into the straightness issues of stock bores as no one wants to believe a 0.012" warp in a barrels bore. I have seen damn few stock bores run true when put between centers on a lathe.
When a factory bore is properly broken in they are usually a little more consistent, and foul a little less than if it is not done. The worse the bore is, the more important it becomes, to properly break in the bore.
My preferred method:
!0 rounds, single shot - clean, single shot - clean, all 10 that method.
30 rounds, 3 shot group - clean, repeat to completion.
50 rounds, 5 shot groups, and you get the picture.
After completing this drill , fire 3 or 4 fouling shots, and shoot for record. At this point determine the accuracy and consistency of the rifle.
My new RRA AR15 was lapped at the factory - the instructions said no break in was necessary. My DPMS .308 AR on the other hand had detailed instructions which boiled down to clean after every round for the first 25 rounds, then after every 10th round up to the 100th round. That was a long, long day! And it was a lesson in patience too since the first thing any new gun owner wants to do is shoot his new gun! But after spending over $900 I guess it would have been stupid not to do it. Now it shoots 1" groups and I'm happy! An recent article in Rifle Shooting suggested cleaning a gun over a three day period after the initial cleaning!
I recently went with a Kreiger match barrel on one of my rifles. When I asked about breakin I was told the above.
They did tell me to not get the barrel to hot and clean after every 15 shots. But other then that nothing out of the ordinary.
This ties in with the comment I received about re-cleaning after cleaning because the powder leeches out of the metal after a few days. It was in my "can you over clean a gun" thread. Leech may not be the right word , but the person explained the process to my small brain, and that's what I recall.
I don't meen to hijack the thread, but i was wondering if you should break in a pistol barrel? I have always heard about this for rifels, but what about pistols?
There is no need to break in any barrel. You are just burning up worthwhile bullets and good powder. just shoot that darn thing.
Bolosniper is 100% correct. As to factory barrels, it's absolutely necessary to break them in for best results IF you're NOT going to handlap them. I prefer to handlap all my barrels except for those high end aftermarket rifle barrels done so at the factory. There's no way in hell I would EVER consider Tubb's final finish firelapping kit as I've had to replace 2 barrels from customers that treid it and messed them up. To me,firelapping is the lazy way to TRY to handlap barrels but don't get nowhere near the same results as you cannot feel burrs or rough spots as when hand lapping.
Pistol barrell break in
Stalkingbear is dead on. I saw a test report on a $1200+ Kimber .45 that was intended for competition and it said in passing it was quite accurate after a 1000 round break in. I saw another .45 report (probably Kimber) that accuracy starts to drop after 2000 rounds. Kind of a small window. Does anyone know if cryonizing would help to extend the life?
I've got close to 12 or 15 thousand rounds through my Kimber. I have yet to see a drop in accuracy.
There's been claims that cyrogenicallye freezing extends the life but I havn't paid close enough attention to round count to see the difference. I DO KNOW cyroing a rifle barrel WILL keep it from walking as it heats up.
Thanks Matt. That was the only thing holding me back from picking one up although I still think that all target guns should be finished before leaving the factory. Remind me back in S&W's lousy years getting a model 42 and bleeding all over it and the box unpacking it. I let my thumb touch the muzzle. Burr so huge and dangerous they should have offered it as 'Second Line of Defense' option.
The Kimbers are ready to go right out of the box as far as accuracy goes. I don't know if the mainspring needs to stretch, or if it has to do with the second generation firing pin block, but after a few hundred rounds, trigger pull smooths out and drops about a pound. IIRC, the break becomes more crisp as well.
can anyone explain what does cryo treating a barrel entail. i know i dont have the equipment to do that but i work in a cryo shop right now.
You cool it to -360* then you slowly bring the barrel up to 100* then back down to room temp. This is said to relieve stress but if your barrel is made correctly there will be little to no stress in it.
Barrels that get stress are button rifled and or flutted. Flutting will most deffinatly cause stress in a barrel you are cutting metal away from the barrel after you finish it.
I didn't break in my Remington 700 VLS barrel and she will shoot .4" 5 shot groups at 100 yards. My 308 will not shoot over .5" 5 shot 100 yard groups no matter what I do to it.
We used to have similar discussions when I was an undergrad . . .
"So, hey . . . shall we clean the seeds out of it, or go ahead and smoke it with the seeds in it?"
The US Army AMU, among others, has done R&D to determine whether or not a cryoed barrel does have a longer life span than a non-cryoed bore does. The data strongly suggests that it does (barrel grade steel elicites abrasion resistance that is approximately 528% higher than non-cryoed barrel steel. The results were that cryoed bores last about 4 to 5 times longer than their non-cryoed cousins.
Another major benefit of cryogenics is that there is actually an exchange of atoms at the sub-atomic level, and that means that a piece of material that has been subjected to cryogenics is that the molecular structure of the material will be identical throughout the entire piece of material. Now what does that mean? It means that the material will not have "hard" martensite molecular structures, and "softer" austenite molecular structures in the material that will cause a variation in the amount of tool flex. The material (in this case we are, of course, talking about barrel grade steels, and receiver grade steels) will be of uniform molecular structure and hardness (martensite) and the tool flex will be constant and consistent. It is then possible with tight running toolroom machines to ACTUALLY hold tolerances of 1 or 2 10,000ths of an inch throughout the entire machining process.
I agree, big difference between factory and match; and how to break-in. I think any factory barrels that need over 60 rounds for break-in will ware-out before they are broke-in. I did use Tubb's on a used .260 Ruger M77 MKII, it has very, very long lead. I think it made a little easer to clean, but other than that a waste of time and money.