This one got me stumped.
I cast about 300 of my favorite .45 cal 330 gr bullets this afternoon and they were averaging about 10 grains lighter than normal with the same metal I always use but the finish looks kinda granular. The only thing different that I can think of is that it was 24 degrees outside while I was casting. In warmer weather they average from 328 to 332 grains and today they were mostly 320 to 324 grains with the whole range going from 318 to 326 grains. I'm kinda ocd when it comes to procedure. So did I miss something or is it temperature related?