Fire Lapping

[slug]

There is some controversy over the use of firelapping to smooth out a rough bore for lead bullet shooting. This method was pioneered by Veral Smith who wrote the book, literally and figuratively, on cast bullet shooting. Some shooters vow that they will never do it to their rifles, while others swear how helpful it can be.

I've fire lapped quite a few rifles and did another this morning. It was a C. Sharps 1875 model in .32/40, with plain base bullets.

I fired ten rounds of a carefully assembled load, then twenty-nine lapping loads with cleaning after every few shots. I then cleaned the bore again and fired ten rounds on another target. The photo shows the results. Please discount the .22 holes in the target.

The first target had a flyer and so I just measured the best nine out of ten on each target, The CTC group on the first target was 3.34 inches and the second target was 2.41 inches. That's about the best that can be expected from six decade old eyes and just a single front rest. The targets were at one hundred yards, so now I think that I'm ready for two hundred.

 

[tjsudbury]

What kind of lapping compound is used, and how are the loads made up? Just might have to try that.

 

[Musketfire]

I am curious do you add some sort of grit/abrasive to the lead when you cast?


Or do you mean just fire many times with regular ammo?

Lets not get all occult here, plain talk is best when it comes to my arms!

 

[slug]

Veral Smith runs Lead Bullet Technology and sells a very fine lapping compound. This is much finer than valve grinding compound - don't ever use that.
The compound is smeared on a small steel plate and a lead bullet placed on it.
The bullet is then rolled along the lower plate with another plate above it, embedding the compound into the bullet.
The bullet is then loaded over a small charge of pistol powder and fired. I used about 6 gr. of AA #9 because I have a couple of ounces from long ago.
If the barrel is pretty smooth, I clean it every five shots or so.
If the barrel is a bit rough my sequence is:
Fire 1 shot, clean. - three times
Fire 2 shots, clean - three times
fire 3 shots, clean - three times &c.
I have one nice Long Branch Enfield that took about a hundred lapping rounds before it would shoot well with lead bullets.
Usually, I just do about thirty. If it's a hot day, don't let the barrel get too warm.
The lapping removes the microscopic burrs left over from the rifling process. There is no noticeable change in the bore, but they shoot better. This helps if the bore has some light pitting also.
PM me if you have any more questions.