Back to a topic from last year. I've dug out the Sharps conversion carbine that I semi-permanently acquired last year and slugged the bore. As the barrel was relined and has 3-groove rifling, I can't get an exact bore diameter, but did get the following information.
I measured across one land and one groove. Assuming grooves are approx 0.005", I guesstimate the bore diameter to be:
Driving bullet completely through bore = 0.512
Driving just into the barrel at muzzle end = 0.516
There appear to be areas of different diameter down the length of the bore, as shown by the data above and the force to drive the slug varies quite a bit in several areas. The bore has light pitting, but is actually quite clean with strong rifling.
I've never been able to get any sort of accuracy out of the rifle, even though I tried bullets from 0.512 to 0.515 diameter. I had a recommendation early on to try a hollow base bullet to help deal with the situation. The Lakota 378C mold (325 grain) was recommended.
Do any of you have any opinions, ideas, etc on the use of the hollow base mold or any other options?