Kyrat, how do you fire lap a rifle?

[Wildthang]

I overheard some guys talking about fire lapping their rifles. Seems they put gritty stuff on bullets and shoot the heck out of it. Wouldn't that damage the rifling in the barrel!

Please help oh Master of guns and wahoo killers!

[kyratshooter]

Fire lapping is the process of shooting bullets through a rough bore to smooth out the sharp edges of the lands and grooves.

It was the lazy mans answer to standard lapping of the barrel that was necessary after the grooves were freshly cut in a rifle. The old process involved pouring a lead cast of the bore around a stick, coating that with lard (or whatever you had) and polishing the rough spots off the bore. It was part of the hand work involved with making fine rifles back in the old days and made the difference in cost between cheap rifles and premium rifles.

I am not sure what they refer to as fire lapping today but back in my dark years of dealing in alchemy what we would do was pour some cast lead slugs and lube them with valve grinding compound. We would then load them ahead of just enough powder to force them out of the barrel and fire about 100 rounds in this manner. At the end we had either polished the burrs off the rifling or we had ruined a good rifle, one or the other.

Back in the day we were searching for the elusive 1 MOA which no one but the gun writers of the day could achieve. Fire lapping, moving barrel pressure points, glass bedding (Pillar bedding), free floating and tuning for barrel/stock resonance, speeding lock time and trigger tuning was all part of the magic of achieving tight little groups and once you learned these secrets you shared them with a select few.

Modern machine work has eliminated the need for lapping bores for the most part. Today a Savage Axis that costs $275 will shoot MOA out of the box with factory ammo, less with reloads. Why would you want to go to all the trouble of fire lapping?