revolver throat to size question

[GREENCOUNTYPETE]

how much should your revolver cylinder be sizing down your boolit before it hits the barrel


I have a super blackhawk I slugged the cylinder and I get .431 the barrel i get .428 in the groove

but I have a lee tumble lube 240gr swc mold that is dropping more like .436 I know in this design I loose some just putting them in cases


I hadn't remembered them being this big before but i just dug a few out to measure after looking at a thread about needing a fat 44 for handi rifles in 44mag

is this too big or with the small bands of the tumble lube design is this not really an issue

I had loaded and shot these a while back and they worked fine , I just wondered if this is causing undue stress on the cylinder

[DougGuy]

If it is a real hard alloy it can raise pressures by as much as 5,000psi to fire them through undersized/tight cylinder throats. If you have a max load that is at the edge of the recommended load data, and a hard alloy, it may raise pressures well into Casull pressures, which you would not want to do in a SBH. If you have no real pressure signs, not having to beat the cases out of the cylinder, primers aren't totally flattened, you are probably okay where you are.

Obviously the softer the alloy, the less resistance there will be to firing them through cylinder throats smaller than boolit diameter.

Truthfully, the throats shouldn't be downsizing boolits at all. You size the boolits like you want them, and to keep them that size you ream the cylinder throats .0005" over the boolit diameter. This is typically how it -should- be but if you are casting and using the boolits as dropped from the mold in a rifle with a larger groove diameter, and want to use them unsized, and you have no pressure signs in the SBH, again, prolly good to go like it is.

[GREENCOUNTYPETE]

being as i am running 44special loads in the 44 mag , I am probably ok then but if I step up to mag loads I will size them

actually they make the SBH shoot rather high , I have a taller front sight but haven't installed it yet , I also got a 200 gr mold I will have to see how they drop when I get around to casting them