I have a brass Mt. Mold for the 357 mag. When using ww plus a bit of lead free solder, the bullets drop out at .357 dia. When using straight lino, they drop at .3585, which I prefer.

I am seeking an affordable way to increase the cast dia. straight from the mold.

Will adding mag shot increase or decrease the dia.?

Thanks,
Jeff

It's Antimony that increases the as-cast diameter. Wheel weights have more than lead shot so just about anything you add to wheelweight alloy will reduce the diameter. The exception is Linotype or Stereotype metal which will increase it somewhat.

1-2% additional Tin shouldn't have really made a noticeable difference, how much did you use? Since lead-free soldr is 90%+ Tin, you should basically treat it as pure Tin.

Use a bullet cast in that mold to lapp that mold. I have done it numerous times with AL & Fe molds, nothing to it.

Assuming your "Lino" is really Linotype, it'll flow easier than WW metal with a little tin added and fill out moulds better. Turn up the heat 25 degrees and see if you don't cast fatter bullets with both alloys. I assume you have a casting thermometer.

MC

Assuming your "Lino" is really Linotype, it'll flow easier than WW metal with a little tin added and fill out moulds better. Turn up the heat 25 degrees and see if you don't cast fatter bullets with both alloys. I assume you have a casting thermometer.

MC

I increased the temp. and added tin. Success! .360"

Next, I will do WWs plus tin and keep the temp of the melt up. I think the temp was the root of the problem.

Thanks,
Jeff

JRR,

Only change one variable at a time to facilitate the learning process. It's doubtful adding tin to the "Lino" did anything to promote better fill-out... you're probably wasting precious tin. Are you casting with your melt at about 750F now?

MC