I did a search thing but couldn't seem to find anyone who talked about the best powders for "light" and "heavy" bullets in the 300 UM.. I have this rifle on the way from the smith.. the 2 powders I have heard good things about are H1000 ( which I like ) and 50 BMG... but what about RETUMBO?? the bullets I am planning on trying are... 175 gr SMK.. way over looked.. should be a lazer to 500 and a good "inside of 1K" bullet for deer.. 190 gr SMK mostly outta respect... the 200 and 220's.. mostly the 220's... I have thought about some a-max's Boyd I woulda e-mailed you directly but since it was hard to find doing a search I thought everyone would like to know... ( you can e-mail me your secret load so Darryl keeps wonderin' ) Also is there a huge difference between the Fed 215 and the 215M ... ie: enough to make a difference???