Casting your own balls

[little seacoast]

Hi, I have recently started casting 2.25" zinc balls for my mortars and cannon. The new mold has a 1/2" casting sprue and works quite well. The problem I'm having is removing the sprue after casting.  Can anyone suggest a tool which will cut this off while still warm rather than hacksawing it off when cool?

[Double D]

No, but bolt cutter works well. 

I will predict you will really like zinc!!!

[rampa room artillery]

on my lead i use to use a sawzall or a chop saw.

 just got to find a way to hold the ball for the chop saw. 

rick bryan N-SSA

[little seacoast]

I cast ten 2.18" balls for the Parrott rifle this afternoon and when weighing them noticed a small discrepancy.  None of the balls have noticable defects but the weight varies from 21.9 oz to 22.6 oz.   The majority are right about 22.5 oz.  The sprue was kept molten for 30 sec. after pour and no voids noted when removing sprues.  Normal variation?  I'll shoot them anyway but was curious as to the cause. Thanks, LS  

[Cannoneer]

That would have to be caused by internal voids; wouldn't it?

[Max Caliber]

When I started casting lead balls around that size for my 3/4 scale gun, I had the same results. If you cut into one of the light balls with a hacksaw, you should find a void somewhere between the sprue and half way down the ball. Making sure the mould is good and hot and having enough sprue capacity to feed the cooling ball should cure the problem. I usually heat my mould by casting balls in it until I start getting good casts, returning the bad casts to the melting pot. A large capacity sprue is very inportant in large capacity molds.

[Cat Whisperer]

From casting MANY bullets (I reload for a couple of dozen calibers) three things  that will affect weight (other than variations in alloy):  Mould temperature, alloy temperature and how tightly you hold the mould closed.  Add to that some variation in fill from how high the ladle is over the mould.

Consistancy is gained by monitoring the temperature, keeping a steady pace, and watching that you do the same things again and again.

[GGaskill]

When we were casting zinc soda can shot at last year's CBC² I, we had to keep a propane torch on the sprue so that it would stay liquid until the whole of the shrinkage was satisfied.  Doing that produced shot of small variation in weight.

[little seacoast]

What was your variation in weight?  I'm seeing a couple 10ths of an ounce range on most.  The range was 7/10ths oz. lightest to heaviest.

[Double D]

I just weighed the 4 pop can balls I have right here in the house from last years pour.  Here are the weights in ounces.

35.98
36.68
36.33
35.05
average 36.01   Difference lightest to heaviest 1.63 ounces.

Balls are 2.59 diameter and Georges round ball calculator says they should weigh 2.2 lbs each or 35.2 ounces.

[GGaskill]

That weight is based on the quoted value for density of the metal.  If it is different, the weight will be different.