I was checking the fit of some cast bullets (LBT 240LFN)sized .411 by setting up a couple dummies in my RBH 41 Bisley they would drop into 4 chambers but would not completly go into 2 others unless I slowly spun them in the chamber a little at a time also the throat in the 2 appeared darker on one side than the other. Whats the sollution?Is it a simple matter of using A smaller bullet .410?

Dasbear

Clean the cylinder thoroughly, then slug the throats & see what you have. You may simply have a couple of chambers that are a little tighter than the others. The cylinder may simply be dirty. Remember, the factory test fires new guns too, then just gives them a quick wipe down before shipping.

dasbear,

clean the chambers carefully as recommended by anachronism. Then see if you can borrow some plug gauges, 0410", 0.411", 0.412". Measure and record each chamber throat ( write it down ). If you have some tight throats, you can open them up to a uniform diameter, with all the other throats, by making mandrill out of a slightly smaller dowel. Cut a slot in the end of the dowel to hold a wrap of emery cloth (>=400 grit). This "hone" should fit snugly in the "tight" cylinder throats. Gently turn the mandril in the throat and measure frequently with the plug gauge. If you have a drill press and vice, it will keep in alignment. Turn the drill press by hand or at a very slow speed. That should uniform the chamber throats.

thanks for the advise from both of you. I have shot a box of factory stuff down the bore and gave it a good cleaning after so it is clean. I will continue with slugging throats then possibly honing as dwag recomended.

Dasbear