View Full Version : What is fire lapping?

March 23, 2011, 10:40 PM
I have a rifle that is fairly new and the bore is has a dull finish. I have cleaned it with Hoppes 9, Rem Oil, CLP and the bore is still dull and the patched continue to come out with some black. So will fire lapping polish the bore. ( the lands or groves have a dull shine). The rifle is and M1 carbine by Auto Ordince.

Ideal Tool
March 23, 2011, 11:25 PM
Hello, carprivershooter. Fire lapping is done by forcing an abrasive grit into the surface of a bullet, either lead or jacketed, and firing a with a VERY light charge of fast burning powder. I have done this with an original 1898 Krag rifle, & 1903 Sprgf. The problem is that if not careful..the throat can be lengthened. Also, groove dia. can increase. In my case, the bore was loose about 6" forward of chamber..this was common with turn of century military arms from powder erosion. F.L. cured problem, brightened up bore, even grooves, very very slight taper..measured in tenths of thousand. Accuracy greatly improved.
That said, I don't think you need, or should use such a drastic procedure on your rifle. Have you tried JB compound on a tight patch as per instructions? And after that, some JB Bore Bright..this usually will brighten things up nicely. Just be sure to use a good quality cleaning rod and rod guide. Best of luck!

March 24, 2011, 01:10 AM
Fire Lapping shouldn't be done for cleaning purposes. ;)

Scrub. Scrub. Scrub.

As long as the patches are coming out black, that bore is dirty.

March 24, 2011, 02:22 AM
it might be that your gun has had molly bullets shot through it or the bore is molly coated

if so its going to take a lot of cleaning

March 24, 2011, 08:33 AM
How does it shoot? If good, leave alone.
If not accurate, re-read the post by Ideal Tool and follow advice given.

March 24, 2011, 08:47 AM
I've done this procedure to a new .22 and a new .50 caliber muzzleloader - they both shoot really great. (The .22 is rediculously accurate at 50 yards). I have a new .204 that I will do this to as soon as I get a small enough rod - good luck.


March 24, 2011, 09:14 AM
I thank everyone for their comments. I will first try the J B Bore Bright. TFL is a great place to ask questions. There is such wealth of information in this group of people thank you again.

March 24, 2011, 04:17 PM
Doesn't sound like moly...

I'd soak it with a good penetrating oil, and patch it out once a day for a bit... Thing is, it's probably not going to ever be a "shiny" bore unless you screw in a new barrel.