Has anyone here ever make a bump die?

[Shootymacshootface]

Thank you, I have not fired them yet, but I will be very cautious.

 

[MaxGunsmithing]

What diameter are the cooled 30 cal bullets out of the mold. They should already be more than .308''
Could you not just ease the mold open to get .312'' bullets?

no. it would not be consistent or round and you would end up with a ton of flash and possibly end up with horrible burns when molten lead pours out the open mould. not trying to be rude or mean i just have a lot of experience casting.

 

[Tozguy]

Oops I meant to ease the mold diameter open by boring it on a lathe.
My idea was certainly not to hold the mold open a bit while pouring lead in although I can see now how my post could be interpreted that way.
Sorry.

 

[Firebrick43]

I have opened several lyman dies up that cast undersize bullets by charging soft cast (from the mold) bullet. Do two or three at a time. It helps to have a lathe but it can be done with a drill press as well. Drill a hole slightly smaller than a 8-32 bolt. Put the 3 bullets between to plates of steel, no big deal as to type, I have 2 1x4x1/4 pieces. Smear some diamond lapping compound on the plates and with some pressure roll the bullets between the plates.

Take and insert an 8-32 screw with the head cut off and chuck it in a cordless drill on low speed. Put the bullet into the mold and turn it for 30 secs or so slowly. After doing all three, clean the mold very well, cast 3 more, measure and repeat if necessary.