Hi all, I got a MRC .475 barrel and just chambered it for my 470NE project. The bore has visible rings inside of it all the way down, probably from the reamer or something? Anyway, I'm hopeing that it will shoot fine, but I'm thinking that it might give some fouling problems with cast bullets.
If I wanted to lap it, after shooting to see if it needs it, How would I go about it?
I'm thinking of turning a tight fitting brass jag, then put some 280 grit lapping compound on a patch and run it back and forth in the bore to polish things abit.
I'll have to shoot it first to see if it needs it.
Thoughts?

Proper lapping is done by a very qualified technician by him sliding a long, lead slug up and down through the bore until it "feels" right to him-- it is not something to be left to an amateur. The slug has very fine abrasives on it which smooth and polish the bore; too much action and the bore is a goner. There is a kit out by David Tubb that allows you to "firelap" your barrel by loading his bullets (which have varying degrees of abrasives on them) and shooting them in your rifle. I have read and heard that it's a good system from some and a bad system from others.

Do some research and choose wisely.



Just checked "david tubb firelapping" and found the product name to be "Final Finish." Go there.

Hand lapping a finished barrel is nearly impossible without bell-mouthing throat and muzzle. IF your barrel fouls easily checkout:

http://www.neconos.com/details2.htm

A little time consuming but certainly cleans up a rough barrel. I've used it on 50+ barrels. Always results in less fouling. Often better accuracy.

I've used the Final Finish system on a Savage that had a "rough" looking barrel from the factory. The bor is now like a mirror and the gun shoots .5 MOA. What else can I say?? There are many naysayers to firelapping, but David Tubbs system uses very, very fine abrasives. I personally would not use the NECO system.