Mold dropping undersize

R

Randyralph

New member
Good day all. Just a quick question today, what would be the biggest reason for a mold to be dropping under size bullets. I have a Lyman mold that always dropped @ .452", but something has changed in either my alloy or temp that has the mold now dropping at .451 to .450". The one thing that has changed is I'm now using a new 20 pound lee pot, and I've started to pour at 700 F. My alloy is WW only, with about two feet of 50/50 solder per pot. The alloy and temp. worked great for my .357" bullets, but for some reason the .452" dropped low. Any suggestions.
Thanks
 
I have the same problem, I am new to casting and not very good with the alloys yet. also, having your lead too hot will make it shrink up more when it cools. try lowering your temp first, then worry about alloying specifics. how small is it dropping?
 
I would start out dropping your pot temp down to around 685 for starters. When I pour solids in 45 caliber they usually need less alloy heat to keep the mold temp up. Once they start frosting a little I slow my pour rate down.

I have found that the hotter the mold the smaller the bullets will be. It don't sound right but it works that way. If your preheating your mold on a hotplate you might also turn it down just a smidge as well. I would rather start off with a good rhythm going then have to slow down right off the bat. I don't mind the first few pours being a bit wrinkled either, and usually just dump them in the sprue can anyway. Put a long folded shop towel in a small pan with one end hanging out a few inches. Then dump your bullets on top and you can pick up the end and roll them to the other side of the pan and see real quick if they are good or not. If not, just leave them be and get on with casting and dumping. Soon as you see the good ones roll everything to the far side and keep going.
 
You must log in or register to reply here.
Back
Top