Recently came by a Ruger .30 Carbine revolver. Here are the figures obtained by slugging the barrel and cylinder mouths using a Starrett micrometer to measure the slugs:
Barrel mikes at .3092 with some unexpected tightness under the barrel/frame threads. After the slug passed the muzzle moving toward the breech, it moved increasingly easy until it reached the barrel/frame threads. I can fire-lap that out, though.
Cylinder chamber mouths measure uniformly at .3096
Unfortunately, my cast boolit measures a generous .3099 and will not enter the cylinder throats.
Do I look for a smaller boolit, opt for a smaller sizer die for my Star, or open the chamber throats? This boolit is from a Lee 2-cavity mould that drops the most consistent weight of any boolit mould I have ever used. It boringly weighs boolit after boolit at 115.5 grains.
Right now I'm thinking open the cylinder throats. What would you do? Big Boomer