Bullet Casting Woes

[Patrick Chadwick]

I now seat the bullets shortly before going to the range.

So do I. For the very same reason. A greasy lubricant will always penetrate the wad, eventually. Pure wax would probably last a very long time, but greases have lighter fractions that soak through the wad material - quite fast in warm weather, as you have discovered.

But what bothers me more is the variation in bullet weight you are observing. What is the variation?

The first few casts in a session will usually show sub-optimal filling of the mould, and be underweight. The very last casts, really getting down to the bottom of the pot, will also be dubious, maybe embedding some crud off the bottom of the pot. And any flashing on the cast indicates that the mould was not quite closed, and the bullet is likely to be noticeably overweight. But the main flow should be within the sort of range I quoted. However, you must keep on casting at a steady rate, not stopping for tea and then restarting, so that the mould keeps a constant temperature. If your arms are aching and you need a break, park the mould over the melt - as close the to melt as you can get it, without dunking it. This helps to maintain a good working temperature.

Try to pour at a constant rate, and have a similar quantity of lead as the blob on top of the cut-off plate each time , so that the final fill as the lead in the mould shrinks and draws in material from the reservoir of the blob is also fairly constant. In short, every part of the operation should be as consistent as possible.