+1I'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.
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.Shooting suggested cleaning a gun over a three day period after the initial cleaning!
I've got close to 12 or 15 thousand rounds through my Kimber. I have yet to see a drop in accuracy.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?
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?
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.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.
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.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.
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.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.
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.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.