i have heard of lapping a barrel, and know of one or two techniques, but want to know more before i start

Hand lapping is done before the barrel is installed on the action, cut to length, and chambered. It involves casting a lead plug around a rod, putting some lapping compound on the plug and cycling it through the barrel to lap it. It's kind of an art form to get it right, it takes a very experienced hand to do it. It tends to bell both ends of the barrel so it has to be done before installation. It isn't something to be done at home.

Fire lapping involves firing a bullets through the barrel with various grades of abrasive compound coating them. Opinions vary about it. My opinion is that it's a dumb idea to shoot bullets coated with sand down your barrel and that if you're going to try it you had better be ready to buy a new barrel because there's a pretty good chance you're going to ruin the one you've got. However, if the one you have shoots like crap to begin with then I guess you don't have much to lose.

[ 07-01-2003, 02:47: Message edited by: boltman ]

If you do decide to fire-lap your barrel may I suggest the Tubb Final Finish. It is a entire kit with 5 compounds in decreasing abrasiveness. Many people swear by it, even using it on new barrels to remove any tooling marks. I have never personally tried it, but I have never heard of anyone damaging their rifle with Final Finish.
More info HERE.

Fire lapping on custom barrels is a BIG NONO . However (ain't that a great word to use instead of "but"?), on cheap barrels or some factory barrels, it can help a lot.
My latest fire lapping was done on a Rem 700 .375 H&H factory barrel. Before lapping: hard to clean, jacket fouling, accuracy so-so. After lapping: cleans up easily...and accuracy with both cast and jacketed bullets is better than moa.

If you order a custom barrel from folks like Montana Rifle Co., or Lothar and the like there is no need to lap a barrel that they have already done!

Rusty
We band of brothers!

[ 07-01-2003, 17:54: Message edited by: Rusty ]