View Full Version : Rifle bore hand lapping

August 6, 2010, 01:05 PM

I have a Wheeler engineering bore lapping kit I have used it on firelapping a Ruger blackhawk.

Has anybody used this to hand lap instead of firelapping? I have read a good deal about hand lapping but they use different compounds for hand lapping.

I would use it to firelap but its expensive, if thats the only option I will firelap.

August 6, 2010, 01:08 PM
How is firelapping expensive? Just shoot the rounds at targets like you normally would and enjoy the gun. If you pop them off into nowhere not enjoying yourself then yes, accounting for all that ammo is pricey. But you would have shot that much anyways :)

August 6, 2010, 01:11 PM
well i gues I could buy a box of cheap jackedt bullets for the 243 i am trying. but I would rather do it at home.

August 6, 2010, 01:14 PM
So buy a hand lapping kit

Not that difficult :p

For the record... you dont NEED to lap a barrel. I never lapped my savage 12, or broke it in, or any of that garbage and it shoots really good. Same with my AR.

James K
August 6, 2010, 02:11 PM
I have no doubt that some barrels definitely profit from lapping, but the way they are made today any change will likely be minimal and not any better than just firing. After all, lapping (by whatever method) is just speeding up the wearing that comes from firing the rifle. You get a smooth barrel quicker, but you also shorten the barrel life by the same amount.

Yes, I have read those claims that "my rifle wouldn't hit a barn until I used Joe's (or Pete's, or Mike's, or Jim's) lapping process, now I get quarter inch groups at 5000 yards". I take them with a salt block, a grain being too small.


August 6, 2010, 02:24 PM
^ Agreed, if you are tight on cash dont worry about it : )

August 6, 2010, 02:26 PM
these barrels are 30 yrs old they are quality manufactured rifles ones a ruger M77, the other rem 700. without a bore scope I wouldnt lap it since its got over two thousand rounds through it on the the ruger. The rem 700 hasnt been fired it sat in my grandads gun cabinet until my he gave it to me. I shot maybe 60 rnds. through it.

August 6, 2010, 07:48 PM
Are you disapointed in it's accuracy?
Acuracy depends on a multitute of things, and most of which have nothing to do with the finish in the bore!

T. O'Heir
August 7, 2010, 12:26 AM
What makes you think you need to lap either barrel?

August 7, 2010, 03:21 AM
I can see rough tooling marks on both barrels.

Match grade rifle barrel makers are handlapped to a mirror finish. what makes them think they need to lap their barrels

August 7, 2010, 01:56 PM
Yeah, but how do they shoot now?
For sake of discussion, if a rifle shoots 1/2" moa with visible tooling marks, what's to say that after you hand lap the barrel, the group size could increase not decrease?.

Just my 2 cents.

August 7, 2010, 03:44 PM
"Match grade rifle barrel makers are handlapped to a mirror finish"

Yes, but they are lapped BEFORE they are put on the guns. Lapping a barrel that's already been installed is just asking for a messed up chamber or crown.


August 7, 2010, 04:07 PM
Lilja FAQ:


"A. Almost all of our barrels have a bandsaw cut one inch from the muzzle end of the barrel. This indicates that the barrel is not useable beyond that point. When we hand lap our barrels, we do so from each end of the barrel. Because the lapping compound is applied to the lap directly next to the ends, the bore becomes worn slightly oversize. This oversize condition does not extend more than .50"-.75" into the barrel but we put the saw cut one inch back to ensure that you do not use any of the oversize bore.

This same condition occurs at the chamber end of the barrel too, but when the chamber is cut into the barrel, all of this oversize portion is removed with the chamber."

August 7, 2010, 04:50 PM
no they dont shoot .5 moa its 1.5 inches at 100y. the chamber area of the stock has been epoxy bedded, along with front recoil lug, and rear reciever bolt.

I went out and got all the proper tools to do the 243 muzzle crown protector, some heavy cloth patches, and I seated a bullet upside down just out of the case and chambered it protect the chamber. I did it already yesterday I doubt I did any polishing with cloth pathces as lead slugs are used to handlap. But without a borescope its really hard to tell.

August 11, 2010, 04:21 AM
hand lapping is not done with patches, have fun,do things your way,but it is a rare person who has the knowledge and skills to improve a factory barrel,
IMHO,the time to try lapping a bbl yourself is when the bbl is unacceptable and you have nothing to lose.I bought a pre threaded,short chamber cheap bbl once.It copper fouled horribly.A peak with a 10X loupe at the muzzle showed the rifling button had smeared the steel like cheeze.
I charged some cast 30-30 bullets with some very fine diamond lapping compound I used to polish molds with.It was successful,that barrel shot well.
I hand lapped a 40 cal cheap bpcr bbl because when I slugged the boreI there were tight and loose spots.I used a method described in a circa 1930s gunsmith book,I think Clyde Baker.A tapered brass large woodscrew is fitted to a cleaning rod.Within the bore,molten lead is poured around the screw.Without removing the lap from the bore it is allowed to protrude enough to be charged with abrasive.Turning the screw in a bit expands the lap.
After my time and trouble,I came to the conclusion it is better to buy good barrels.I truly do not believe I can improve the Badger .50 that will soon be in a Rolling block.I don't think I can improve a Douglas,Shilen,Lilja,either.I have built rifles with all of those and they shoot.
Have fun!

August 11, 2010, 06:45 AM
I remeber lapping the barrel of a marlin 94cl 25/20 late 80s vintage that just wouldn't shoot. I cast an in barrel slug around a .22 cleaning brush, removed the lead slug, cut a couple of grooves around it to hold lapping compound. lapped the tight spots out where the sights were cut in and towards the chamber. Got it all the same with no tight spots and a shiny mirror like finish. Gun still wouldn't shoot. Haven't had the urge to lap a barrel for the last 20 years.