Lee 405 HB as cast

[armednfree]

I'm casting Lee 405 HB bullets. Just after cooling to the touch they are casting at about .461 average. I do not have a sizer die yet. If they chamber should I shoot them as cast? Will the dimensions change after they sit awhile? Cast from range scrap they seem a little hard. That would seem ok as I intend to push them to 1500-1600 FPS with IMR 4064.

Also, the only way I'm getting good bullets is to contact the mold to the spout, then they are perfect.

[Larry Gibson]

With the range scrap alloy it is probably antimony rich. I add pure lead to my range lead at 1 - 3 or 2- 3 and then add 2% tin. This makes for a much better alloy in the 12 BHN range, is malleable and can be WQ'd to 18 - 20 BHN if a harder bullet is wanted. That mix also cuts down on antimonal wash in the barrel as the antimony is much better balanced with the tin creating SnSb which mixes in solution with the lead for a better ternary alloy.

You will also find that alloy mix will cast better giving good fillout (your bullets may end up larger). Suggest you cast with the alloy at 725 degrees and use a ladle. If no ladle make sure the spout is open up as far as possible to get the alloy into the mould as quick as possible. The alloy cools very quickly, quicker than most realize. Keep the spout about 1/4 - 1/2" from the spout and leave a generous sprue even if some alloy runs off. You want to keep hot, molten alloy going into the mould until complete fillout. Adjust your casting tempo so the bullets come out good but not frosty. I prefer to adjust tempo rather than alloy temp.

If they chamber then you can probably shoot them "as cast". You may find better accuracy that way also. Given the rich antimony in that alloy they will probably increase in size a bit but it's really unknown w/o actually measuring them after 7 - 10 days again.

Larry Gibson