Quote Originally Posted by The Lord Flashheart View Post
Thanks Outpost,

That's a good looking design, assuming the hollow point replaces the meplat (0.18") a 15 degree per side hollow point would be come to a point at 0.34" deep, can the angle be reduced to around 10 degrees?
You cannot "replace" the meplat to a sharp wire edge, because the lead will not flow into the narrow crevice. That's why I suggested that the core pin for the HP cavity be about 0.65-0.70 of the meplat diameter, which works out to about .120-.125".

I have found in fooling with several custom molds, that is the perimeter of the meplat remaining around the HP cavity is less than 1/10 of bullet diameter that the nose will fill out and resulting castings will be poor and irregular. This is ESPECIALLY true if you are using scrap alloy such as wheelweights diluted with soft lead.

1:40 or 1:30 tin-lead without other alloys additions will give the best fill-out without hardening the bullets appreciably, as is necessary for subsonic velocity expansion.

I have used a 15 degree draft angle on several gang molds and the castings release easily and production is unimpaired from an unmodified gang mold. A sharper draft angle such as 10 degrees included angle should also work fine. Some of the fellows who use cast pre lead HP bullets in large caliber air rifles use an eliptically-shaped cavity and this also works well IF the shape is controlled carefully to ensure that castings do not "cling" to the core pin, but release of their own weight when the mold handles are tapped lightly.