Fire Lapping

[MapMan]

Just received the May 2015 American GunSmith. There's an interesting article about "Fire Lapping" and David Tubbs FinalFinish bullets. Anyone have any comments or experience using this product?

I'm not a gunsmith, just an avid reader of anything related to firearms.

Thanks, MapMan

 

[M-Cameron]

eh, ide rather just properly lap it by hand....its really not that hard of a process.

 

[denton]

Firelapping is a pretty drastic action.

I bought a kit once, still have it, and don't intend to use it.

 

[gamestalker]

Nope, I hand lap mine.

Fire lapping can quickly ruin a barrel if your not careful. You can put 20K worth of wear down the barrel, within just a few rounds of fire lapping.

GS

 

[ku4hx]

eh, ide rather just properly lap it by hand....its really not that hard of a process.

This. Been doing it for decades and it's just not that big a deal. To me, fire lapping is like brushing your teeth with a Dremel tool ... you better get it right the first time.

 

[bush3755]

If the fact that thousands of rifle shooters don't fire lap their barrels and get best accuracy with the first several shots fired in a new barrel is meaningful, then fire lapping, like breaking in a new barrel, is a waste of time.

I don't think David Tubb's Schneider barrels he fire laps are any more accurate than the other half dozen top quality ones that shoot bullets just as accurate without any break in or fire lapping whatsoever.

 

[MapMan]

Thanks for the quick replies. It's great to have a knowlegeable source to field questions.

 

[BSA1]

Fire lapping a barrel is a easy project. All you need in the way of special supplies are soft unsized unlube bullets and fine valve grinding compound.

I fire lapped the barrel of my Ruger S.S. .270. I used Clover 0000 lapping compound. Simply smear it into the grooves of the bullet and seat the bullet over a light powder charge. Unique works well. All you want is to push the bullet fast enough so it barely exits the barrel. Shooting the rifle at close range is a easy way to make sure the bullet exited the barrel.

It does not take very many rounds. I fired 20 rounds through my .270. I cleaned the barrel throughly. I then broke the barrel in by shooting regular jacketed bullets and cleaning the barrel after every few rounds.

The results? Well the rifle will consistently shoot three round 1/2" groups at 100 yards. Very impressive for a production rifle.

Now for the rest of the story. I never shot the rifle before fire lapping the barrel so I don't know how much it helped it's accuracy. However I can definitely say it did not hurt the gun in any way.

 

[MapMan]

Thanks BSA1 for the additional input. The article I referred to was written to indicate that the fire lapping the writer used on some neglected rifle barrels netted around an 18% improvement in accuracy. It would be interesting to have a bore scope.

 

[highlander 5]

I've firelapped several Ruger revolver barrels with a kit from LBT,before lapping the barrels were pretty rough after lapping very smooth and a mirror finish. Lead slugs slide down the barrel and the difference in bore diameter is only a few ten thousandths of an inch increase measured with a micrometer.

 

[MapMan]

Thanks for the info highlander 5.

 

[boom boom]

One thing that supposedly makes the firelapping work is that it will produce a tapered bore and can smooth a rough scaly throat. Bore gets more snug as the bullet approaches the muzzle. Supposedly, this type of tapering is one of the tricks that the P14 and 1917 Rifles had as well with their original barrels.

Personally, after doing the research, I would only use it if I had accuracy problems in the first place, a rough bore and throat, and for some reason could not replace nor rechamber the existing barrel. I would not want to do so with a new precision barrel.

I was about to do it to an old 11/1918 Eddystone barrel but instead bought a better WWII era High Standard barrel which were not tapered to fit my 1917 rifle. This made the whole firelapping project a nonstarter--kept the barrel if I ever want to restore the 1917 to WWI configuration. Since the receiver was parkerized anyway, I decided to go with the WWII look in my restoration.

 

[MifflinKid]

I fire lapped two stainless steel Ruger Vaquero revolvers in .45 Colt back in the 1990s when I got into cowboy action shooting. They both had frame chokes that squeezed the bullets down to .448" while the rest of the barrel grooves were .451". Before fire lapping them the best I could do was 3 1/2" to 4 1/2" at 25 yards. After the fire lapping session they were shooting 2 1/2" to 3"". (All shooting, before and after, was done bench rested.)

I used some unlubed soft cast bullets with the Nostalgia Enterprises Company (NECO) Fire Lapping Kit. It took me several hours one evening to prepare and load the lapping rounds and an entire afternoon at the range to accomplish the fire lapping process.

Preparing the bullets with the lapping compounds is a very messy process as the lapping compound gets all over your hands. You must also thoroughly clean your reloading dies when your done to ensure all of the lapping grit is removed. The firing of the prepared bullets take time as you need to clean the barrels periodically and slug the barrels to measure your progress.

The fire lapping eliminated the frame chokes taking the entire barrel to a consistent .451" groove diameter. The barrels are shiny and smooth their entire lengths. Cleaning after a shooting match is a breeze. Before the fire lapping the barrels beyond the frame choke area had long streaks of lead in them after a shooting match. Now there are just specks of lead left in the barrels after a match. Any lead in the grooves can be pushed out using a dry patch after letting some Hoppes #9 or Ballistol sit in the barrel for 10 to 20 minutes.

The Ruger stainless steel is reported to be very hard. I suspect that is true as I had to shoot twice as many rounds as described in the kit literature. But, other than that, the entire process was simple but somewhat time consuming.

I have no experience fire lapping rifles.