I have a Sako A7 I am wanting to get a handload made up for it. It has a 22" barrel and a 1-10 twist. I am wanting a long range load. I plan on shotting a Berger bullet. Probably 150 grain for that extra pop downrange and wind bucking. But could shot 130 or 140 grains to if reccommended. Like to get to be a killer out to around 600 yards. or further if possible. What loads do you guys and gals reccommend? I have heard retumbo is a good powder. Thanks for any info.