I know that max case lenght for a .257 STW is 2.850.When you trim your cases how far under this number do you trim? ANTHONY

.010 '

I agree...the .010 is the normal trim amount for good safety and consistancy....IF you want ...they sell chamber length gauges at Sinclairs for finding the actual length of your chamber and you can trimm from that...or a chamber cast ...but the chamber gauge is quick and clean-easy to use......MOST chambers are usually on the LONG side and they list the trimm length to cover the shortest chamber plus the safety factor....good luck and good shooting-loading!!