I am about to work up a load for my 7mm rem mag for long range hunting. I have 1200 or so Fed 210 large rifle match primers that I would like to use. I will be shooting the 168 accubond lr. 26" barrel. I have narrowed my choices down to H4831, H1000, and Retumbo. I just wondered if ya'll had some insight as to which powder would provide the most consistant results with these particular primers and bullet weight. I've heard that some powders ignite better with non-magnum primers than others. Is there any reason that Retumbo wouldn't do well...like it is a really slow burning powder? I know that every rifle is different, but please share your experiences and advice.