Boolit Sizing ??

[buyobuyo]

Hello, I'm fairly new to casting and I have a few questions about boolit sizing. I purchased on of the Mihec 125-HP group buy molds in 359, and the boolits drop at 0.360". The firearms I want to shoot these out of are a 9mm pistol and a .357 revolver.

Both barrels slug to 0.356" and the revolver cylinder throats slug to 0.3585". For revolver loading, I've read suggestions for both sizing just a hair under throat size to a thousandth or two over throat size, and I've read suggestions for sizing to 1-2 thousandths over bore size to as large as will chamber for auto pistols.

Could I just size to 0.358" and run them in both pistols? I've loaded boolits sized to .385 before for my 9mm, so I know they'll chamber. If I need to size smaller for some reason, how much sizing is too much? And is it better to do it in 1-2 thousandths steps or all at once? Finally, how big is too big for a cast boolit compared to bore size? Or is it fine as long as it's within the right caliber range and chambers in the gun?

Thanks, Jeremy

[Bret4207]

Try it and see. There more I play with cast, the more people I hear from here, the less I think in terms of absolutes. If .358 has worked before then start there and see what happens. When you alter things change only one thing at a time and record you observations. Yes, you can get too fat a boolit, but what happens on firing is dependent of a multitude of variables, so you might get pressure spikes that damage the gun or you might just get a little lead spitting. Usually, and I hesitate to imply there is a norm here, you'll find a truly oversized boolit simply won't chamber. The only guns I've heard much about being able to swallow a grossly oversized boolit are military rifles with some age on them.

In very broad terms a boolit that's about as large as can reliably and easily chamber will do the best job. Just remember that even though cast tends to be far more forgiving than jacketed, you still need to be observant and alert for pressure signs and other problems.

[btroj]

I'm with Bret. Try it and see. That is the only way to know for sure. Like he said- there are no absolutes in shooting.
See what your guns like, then give them what they want. That makes everyone happy.