Phil Coffins
69 Cal.
This maybe of interest to our budding gunsmiths. This re-rifled barrel has tight spots that I will be reducing and in the process polishing the bore. The un-breached barrel is cleaned and a guide bushing is fitted to the breech end. The rod has a 10/32 cap screw in the end to receive the lead. Masking tape is wrapped on the rod to fit the bore and pulled back about 10” from the muzzle. Lead is melted after warming the muzzle than with the rod pushed forward to about 4” short of the muzzle the lead quickly pored in. This forms a lap to fit the rifling and receive the compound. I’ll start this barrel with common fine valve lapping compound then cast a new lap for finer grits. The tight spots are easily felt and these are four inches in front of the breech to about eight inches from the muzzle. I make an index mark on the lap to insure it’s always put in the bore the same way. Once the lap is coated with grit the tightest part of the barrel is lapped till the resistance is reduced. Then a rod that is close to bore size is put in the muzzle end to touch the lead and given a light tap. This tightens the lap and more lapping is done till another light tap is needed to retighten the lap. As the work progresses the tight spot becomes longer and you notice the loose spots more. Ideally by the time you’re done the bore will feel the same full lenght or a tiny bit tighter at the muzzle on this one. This is not easy or quick but makes a better barrel. Laps from other jobs are in the picture to show what I’m trying to explain.
AE66A307-1951-425E-A659-F7DCA4C0B854 by Oliver Sudden, on Flickr
AE66A307-1951-425E-A659-F7DCA4C0B854 by Oliver Sudden, on Flickr