A couple years ago I visited this site and got some great help about using my 7RM out to 600 yds...well, it never happened...life got too busy! But now I have a bunch of time! I have a CZ 550 American 308W [23.6" barrel/ 1/12" Twist] that's a shooter but just sits in the safe...I wanna start using it as a 600yd max long-range-to-me shooter. I want to shoot a hunting bullet that would be good for this type of distances to shoot deer when I get proficient with it...~ 1000 rounds or so I hope. The last time I took it out three years ago it was shooting PMC Ammunition 308 Win. 168gr PSP into very tiny groups @ 100 yds. IIRC these are Sierra Bullets loaded by PMC...don't know if there's any truth to that tho? Does anyone here know? I was thinking of buying some Sierra GK 168grain bullets to reload to start with if so. What type of powder(s) should I start with? What other bullets should I consider and what grain for my situation? Thank you for your help I need it!