Need some good advice on sizing

[Lead melter]

Well, here I am at the learning table again, and find myself in need of advice. I have one of the .413-260-Keith six banger molds that 475/480 honchoed on the way. Also planning to send Boomer Mikey a check tomorrow for the 413640-PB GB he is heading up. As you see both are large diameter boolits for the 41 Magnum.

My question has to do with sizing. I plan to order a Lee custom diameter sizing die, but would like some input first.

My Ruger Blackhawk 41 has a bore measuring .410", but the chamber mouths all measure .411-.412". Should I order the Lee die in .411", .412", or simply lube and shoot as cast? Sizing down to the standard .410" is not going to get wonderful accuracy from a cast boolit. So fire your opinions away.

Also, is opening the chamber mouth that much above bore diameter common? Good thing? Bad thing? :???:

[felix]

If your boolits are going to be hard, make them 412; if they are going to be softer, make them 411. If in doubt, make them 412 and start off with a medium load using slow powder. When boolits fit that tight, don't use fast powders unless down towards the bottom of the scale, more like starting values in the books. Get the 412 sizer. Remember, Marlin rifles are 413, so better get a 413 sizer and be done with it. Just load the pistol with slow powders, about 15 percent below max book value as your MAX. The boolits WILL obturate. You might need some way to size the boolit at the nose area to fit into the pistol cylinders, though. Keep that in mind also. Nose size only the nose with a smaller sizer to make them work in the pistol. ... felix

[mroliver77]

See what size boolits it drops first. Check to see then if and unsized boolit will load easily. If unsized boolit will chamber without forcing I would shoot them loading as Felix sugests.
Yes oversize (and undersized) are much too common.
J

[Buckshot]

.............As mroliver77 says. Wait and see what they drop at. If your chamber mouths are .412" a .413" boolit OD would be ideal assuming it chambers okay. Don't plan on sizing just to be sizing.

.................Buckshot

[Bass Ackward]

Chances are that you will have loads that work best all three ways. .411, .412, or unsized.

But don't assume that sizing is a negative. After all, you barrel is a sizer and .... a deformer.