Fire Lap

[Tatume]

Hello Folks,

Many years ago I bought a fire lap kit from Veral Smith at LBT, but never used it. Now I'm planning to fire lap a stainless steel Super Blackhawk. I checked, the lap compound is still liquid, so storage didn't harm it.

Will those of you with experience please share any advice you have? I've never done this before, and would appreciate any help.

Thanks, Tom

[nekshot]

it works very well, as I have done it a few times. I did get some compound in my die one time and that was a mess to get out. It is a last resort to a problem on my book but I have always been satisfied with the results.

[Piedmont]

You roll the bullet between two metal or glass plates (metal is probably safer but I had some stained glass pieces that also work). One thing, the abrasive that becomes imbedded in the bands will add a touch in diameter, so if you are starting with .432" bullets and you use a ton of abrasive, they might become .435" and might not chamber. So if that happened you would want to use less abrasive or size the bullets down to something like .430 before rolling them in abrasive.

Use fired cases that you decap manually because you don't want to size the bullets down when you seat them. Don't overdrive them. They just need to make it out the barrel. Bullets should be wheel weight air cooled hardness or softer, because you don't want them to spring back in the barrel. You want them to hit a tight spot, cut, then not spring back but just travel the rest of the way down the barrel.

Take barrel cleaning equipment with you. I clean the barrel and cylinder throats every few rounds or at least look at them that often. If leading starts to build in the barrel, get it out of there. You want your lappers cutting steel not fouling or lead.


This is actually easy and simple. I usually do it in stages, like maybe 30 or so the first range session. After you get home clean the gun again and examine under good light. You should see where the lappers have been cutting at the rifling lead and under the barrel threads. Ruger stainless is tough stuff. You may be at this a few range sessions.

You might want to load a big bunch of regular ammo before starting so you can check progress along the way as far as leading and or accuracy.

[44man]

You could shoot them in the back yard or the garage, they make almost no noise. A cardboard box with papers or rags will catch the boolits.
Use just enough Bullseye, Red Dot or so to clear the barrel, you can see the boolit leave. Push the boolit all the way in a fired case.
Air cooled WW is best, too soft does not work right. The abrasive will lose the cutting edges fast so most lapping happens at the start.
Just follow instructions that come with the kit.

[Bigslug]

Pin gauge your chamber throats for uniformity. If you've got any that are tighter, you might as well shoot your fire laps through those.

[Big Boomer]

Check dimensions of cylinder throats first. Make them .0005 greater than barrel groove diameter. Then begin the lapping process that has already been described. Stainless steel is much harder to work with than ordinance steel, especially the variety Ruger uses. Very tough stuff. It may require up to perhaps 4 times as many lap boolits impregnated with the lap as compared with blued steel revolvers and pistols to get the job done. I lap all my handguns, pistols included, to smooth the bore for cast boolits. When done as Veral instructs, you will have a fine choke bore with a .0005 decrease of internal dimension grasp of boolit/bullet from chamber to breech end of bore to muzzle. An increasing grasp of the boolit. Big Boomer

[DougGuy]

Definitely want to have the cylinder throats checked and reamed to .4315" or .4325" before you attempt firelapping, depending on the size of the largest throat. Once throats are sized, they won't swage down your lapping boolits. Stainless Ruger takes about 6x longer to lap that blued, and if the choke is severe there is a good chance you can shoot out the good rifling beyond the choke by lapping enough to remove the choke. Firelapping stainless only works if the choke is minimal.

Edit: Wait a min. Are you lapping out a choke or just want to smooth out the bore and maybe taper it?

[Char-Gar]

Hello Folks,

Many years ago I bought a fire lap kit from Veral Smith at LBT, but never used it. Now I'm planning to fire lap a stainless steel Super Blackhawk. I checked, the lap compound is still liquid, so storage didn't harm it.

Will those of you with experience please share any advice you have? I've never done this before, and would appreciate any help.

Thanks, Tom

Why do you want to do this?

[runfiverun]

you may want to hand lap rather than fire-lap.
it will keep the cutting where you want it and not where you don't.

[Victor N TN]

A friend of mine is also a competitive shooter. He says he has fire lapped 4 barrels. 2 were very good. But he said it messed 2 up. Take that for what it's worth.

Personally, I hand lap mine.

Good luck.

[catskinner]

I have fire lapped a couple of rifle barrels. Slug the bore often since the process does remove steel.

[Char-Gar]

Did Elmer Keith, Charles Askins, Bill Jordan or Skeeter Skelton firelap their handgun barrels? Inquiring minds want to know.

[Tatume]

The firelapping appears to have helped. Although I was unable to detect a "choke" in the barrel, the results speak for themselves. This gun previously had trouble keeping five shots on a paper plate at 25 yards.

[Bent Ramrod]

Tatume,

You did it carefully and correctly and got an even better improvement than most people who follow the directions experience. Well done! Be sure to squish the cases you used for fire lapping so they don't go back through your loading dies.

If I recall correctly, fire (or pressure) lapping was first written up by Merrill Martin in Precision Shooting in the mid '90's. He set up a company, Nostalgia Enterprises Company, which offered kits and instructions (taken from his writeups on the subject) on how to do the work.

(I think he was also the guy behind the Molybdenum Disulfide coating procedure for jacketed bullets, which came out about the same time.)

The company was sold (I believe) and became NECO.

Keith and Skelton had gone to their rewards years earlier, and the other two were probably done with gun testing by then, if not retired outright. In any case, as powerful and influential members of the shooting sports media, they would have been able to return any gun with a complaint and gotten something more than a letter stating the gun had been retested at the factory and shot well within the factory's standards. They also had their pick of pre-war, hand-fitted and finished guns, and good gunsmiths at their beck and call, so they would not be expected to have these troubles with their personal firearms.

I don't think for a moment, though, that any of them, especially a natural experimenter like Keith, would have denied the benefits of fire lapping if they had been shown that it could improve accuracy. And, properly performed on a troublesome firearm, it often does, and should do no harm.

[msinc]

Another plus for hand lead lapping...it is much faster and way more effective. It is not hard to do at all. Nothing against "fire" lapping, it can certainly work. It's just no where near as fast or effective as doing it by hand. I can have a bore lapped in the time it takes to load the bullets with the compound, let alone load the rounds. Biggest question to me is; how many lap impregnated bullets have to pass thru a bore at a microsecond each to equal 3-4 minutes of hand lapping {where you can dwell on the tight spots}????

[dubber123]

The firelapping appears to have helped. Although I was unable to detect a "choke" in the barrel, the results speak for themselves. This gun previously had trouble keeping five shots on a paper plate at 25 yards.

And that Charles is why he would want to do this It works very well, and has shown an improvement in the dozen+ I have done, sometimes dramatic as in this case. It's nearly impossible to mess it up.

[DocSavage]

I've used Veral Smith firelapping kit and it worked quite well. Used it on my Blackhawks and Redhawk revolvers. I have a blued Bisley in 45 Colt whose barrel was quite rough push a lead slugdown the barrel felt like a sewer pipe. After firelapsing barrel was smooth as a piece of glass and minimal amout of metal removed maybe .0005".

[bstone5]

Have hand lapped many barrels. Always worked for me. Lapping a 22 rim fire barrel with a little taper, tight at the muzzle, will greatly increase the accuracy of the barrel. All barrels shooting lead bullets usually shoot better after a little careful lapping.

[white eagle]

alot of custom barrel makers lap their barrels

[Oklahoma Rebel]

was this revolver a new one? I am planning on buying a ruger super Blackhawk bisley hunter in 44 mag next spring, do people still see barrel constriction in the area of the frame? would love to not have to lap a new barrel, but I will still check the throats and have them reamed if need be, definetly want those all identical! travis