I couldn't sleep last night, so decided around 3 am I should give the new to me mold a try. I ended up with ~75 decent looking bullets, but many with rounded driving bands. I was casting straight ww's, and pre-heated the blocks by dipping in the melt. Typically, I find rounding caused by a too cool mold, but this seemed to be too hot. I believe casting another mold along side this one would have provided sufficient cooling.

Just wondering if there are any tricks to casting this mold. Hopefully I'll get to put a few rounds down range this week.

Paul -
Preheat is mandatory. Hot alloy is good. 009 did well for me at 750 from bottom pour Lyman 20 lb. Used WW and another alloy (unknown but have 300 lbs of it); both worked well.

Paul,
Have you replaced the Sprue plate with a thicker new one that Lyman makes? That might help a little. Like you say, I normally cast with at least 2 moulds to keep the temps in a good working range. Good luck with that golden bullet mould. I just managed to find a 358318 mould for my Max carbine and pistol barrels...250 grain round nose.

regards,
Graycg

After a long walk to think about important stuff, I believe that the advice of a thicker sprue plate is spot on. I believe what is happening is that the sprue and bullet base harden too quickly, and the bullet is sucking in around the lube grooves. I have some 1/4" tool steel and will have to make up a thicker plate when I get a chance. I'll also have to do that for my 200 gr WFN mold, as it was a converted commercial mold, and has a thin plate, and also suffers from rounded lube grooves when cast hot.