New barrel

[drknite]

When installing a new barrel be it on a new build or replacing an old one is it necessary to use something like JB bore paste or some type of cutting compound to remove any frays or minor in perfection left over from the manufacturing process?Basically lapping the barrel or is that something that the barrel manufacturer takes care of during the manufacturing process? As I have a lot to learn I was told by a high level shooter he does all his barrels when new.Is this a common practice among the better shooters?

 

[Jerry H]

RF barrels do not "break in" like a CF barrel. Weather the chamber has been cut with a reamer or a boring bar, it will still have sharp edge swarf in the lead and radial lines from the cutting process. The heat, pressure, and jacket material of a CF will quickly smooth this out. This is where the one shot and clean method came from. In a RF this would take forever. This area needs to be finished smooth by an abrasive action. JB, IOSSO, etc are way too fine to do this quickly. I use a much coarser grit lapping compound packed in a stiff bristled plastic brush. This needs to be done carefully as you can damage the barrel.

 

[drknite]

I have a lot to learn but this may explain why someone sells a gun they think doesn't shoot, and later it turns out to be a killer rifle. Seems using a type of cutting compound just speeds up the process that shooting would do over time. Thanks Mr. Jerry.

 

[Jerry H]

I started using this in the early 90's to eliminate the break in process in CF and tried it when I got into RF and it works well with it as well.

 

[tim]

I have a lot to learn but this may explain why someone sells a gun they think doesn't shoot, and later it turns out to be a killer rifle. Seems using a type of cutting compound just speeds up the process that shooting would do over time. Thanks Mr. Jerry.

It's also among the absolut best ways. To f..k up a new barrel if you don't know what you are doing. Jerry has lots of experience, more than most.
The better rimfire barrel fitters will have this attended to before it goes out.

 

[drknite]

I have a friend that is an excellent machinist doing the work for me. He has built several rifles recently and all have turned out to be very good shooter's. I have complete trust in him that he will get it figured out because he is a perfectionist.

 

[tim]

I know a few machinists. I know some of the best CF gunsmiths on the planet. None of them want to do rimfire barrels. You might want to ponder that.

 

[drknite]

That tells me it must be extremely difficult which kind of leads back to my original question. Are there any special procedures done to help make the barrels shoot their best?

 

[Fred J]

Clean the bore

If I had just received a rifle with a new barrel installed, I would run a cleaning patch through it before I ever fired it. Better safe than sorry.

 

[Wilbur]

After cleaning a new barrel, shoot it. If it doesn't shoot well THEN do whatever you think you need to do.

 

[drknite]

Thanks Mr Wilbur. Bear with me. I'm learning. Being a coon-a** we sometimes take a little longer than most.

 

[Dennis D.]

This is a case where the quality of the work makes a huge difference. A well cut rimfire chamber takes very little cleaning up. A snug cleaning patch and a little ISSO or Flintz short stroked will polish up the leade easily. It will also clean up just by putting a couple thousand rounds through it. If properly done the difference from a freshly cut chamber to one that's broken in is there but it's small. Clean it well and shoot it first. If it doesn't shoot then go looking for problems. Don't cause any before you try it out.


Dennis

 

[drknite]

Thanks Mr. Dennis for the advice.