i shoot a 300wm and have for years. first thing i would suggest is to have someone watch you very carefully as you send a few rounds down range...or better yet set up a video camera and film yourself then go home and watch the video to make sure you dont flinch as your shooting. second pick up a lb of reloader 22 and some CCI250 primers...personally ive NEVER had any luck with H1000 or fed 215s. also as D.ID said you need to know your OAL to your lands...i shoot 208g BTHP hornadys in my 300 and they DO NOT like a big jump. the 300wm is finicky so make sure you keep tight notes on loads/changes and make absolutely sure that you do every thing exactly the same every time.