Break In New Gun

[Pappabull]

I have an A-Bolt in 300 Win Mag. When it was new I worked up a load for it and that load worked good until I had about 100 rounds through it and then it did not group well. I had to work up another load for it.

I was told that it is common for new guns to do that around 100 rounds, is that true? Do the new guns have to be broken in?

Thank You
Pappabull

 

[muzz]

They should be broke in when first bought.

 

[buttshot]

I have two new guns, a 338 mag and a 300 mag. Neither one will shoot a group as small as my older 300 mag. I am currently working on some loads for my 338 and then I will work on some loads for my new 300 mag. I have been told that when you buy a new gun to either shoot about 100 rounds or use a lapping compound to break in the barrel. I don't know enough to lap a barrel, but I do like to shoot. People have told me that a barrel won't brake in until you shoot about a 100 rounds. If you can get rost495 to respond, maybe he can explain how to lap a barrel correctly.
Something to do with the riflings and filings left after the machine work.

 

[RELH]

LAST EDITED ON Mar-15-05 AT 10:32PM (MST)[p]PappaBull;

You should have done the breakin when the rifle is new. Since you failed to break it in and now have fired 100 rounds, you have a copper fouling problem that has caused your groups to open up larger in size. You will need to use a copper removing solvent to get rid of the copper deposits in the barrel. Shooter's Choice, Sweet's, and Butch's bore shine all make a good copper removing solvent. Just follow their directions and get all the copper out befor you start any breaking in of the barrel. I will repeat this, YOU MUST GET ALL THE COPPER FOULING OUT BEFORE ANY BREAKIN OR BORE LAPPING.
you can do a web search and locate several sites that will tell you how to break in the barrel and help stop or slow down the copper deposits in your barrel. I do not recommend bore lapping to persons who have not been trained to do it. I have seen too many rifle owners end up ruining their barrel by trying to lap it, But before any barrel breakin or bore lapping can be done, all the copper must be out of the barrel.
you will have about 1-2 hours of work to do with the copper solvent remover before you end up with a clean barrel. you can also locate web sites that will tell you how to remove the copper with copper remover solvents.
Recently I have seen posts where hunters have posted information that they heard that you do not have to break in a new barrel anymore, your experience is what happens when you fail to break in a new barrel. Some of the best barrel makers around include information on how to break in your new barrel, this should tell every rifle user something about if they should break-in or not break-in a barrel.
RELH

 

[RANGERCON]

LAST EDITED ON Mar-16-05 AT 05:34AM (MST)[p]Just to add to what RELH stated. You might want to try Barnes CR10 copper remover. It's the best stuff I ever used, and is less messy than Sweet's.

Be sure NOT to leave the Barnes in the barrel for over 15 minutes!
I also like Remingtons Bore Cleaner. Some folks don't like the fact that it's a little abrasive, but I use it about every 100 rounds or so with no problems on several pistols, carbines, and bolt rifles.

BTW, what load are you shooting?

 

[rost495]

Its been covered well. I also will suggest a product called copper melt(I think thats the name-- its locked in my safe) Its not cheap, comes in a stainless bottle with an eyedropper. Its an enzyme and it cleans as well or better(better the few chances I've had to use it) than Barnes or Sweets.

There is a thread on longrangehunting.com that goes over it also.

Plus you don't have to really actually lap a barrel but going over the throat area after all the copper is gone with a patch over a worn brush and something like JB paste may help get out carbon etc..... and might help smooth the throat some.

That being said if you have to lap-- use the system from David Tubb - firelapping with coated bullets. On a junky factory tube its the first thing I'd do to it.

Jeff

 

[mickeyelk]

Last year I also bought a M77 Ruger 300 Win Mag. I figured I'd buy some good ammo and made the choice of Black Hills Gold Ammunition, in the 180 grain size. From the get go it never shot close groups. After 3 shots I cleaned the gun with Boreshine, and shot 3 more times and so on and on. I did this for the entire box, letting it dry between shots and cooling off. I cleaned it as well as possible and its now in the gun case awaiting my next shooting. I have since then purchased two different types of shells and we will see if they shoot better. Maybe I also have a copper fouling problem. How can I see it in the barrel? Thanks! Any other comments welcomed. Kerry