RCBS k-250 mols questions

[kooz]

I have a RCBS k-250 mold that drops bullets a little to small, it is not a consistant problem so I must be screwing something up with my temps is my guess. What is the basic temp rule for getting the maximum diameter ? I am using clip on WW's with a pinch of tin, about 1/4# tin to 20# of WW's. I am using a bottom pour pot and running the temp at 710-750 degrees. thanks

[Lloyd Smale]

Id double the ammount of tin your adding and cast them a little on the hot side to see if that helped. i wouldnt hold my breath though. You are probably going to have to lap that mold to get it to the size you want.

[MakeMineA10mm]

Pouring technique? (Bottom pour or ladle?) and are you leaving a good-size sprue for the boolit to draw on for fill-out as it cools?