I have been trying to find a good load with the 220g SMK out of my .300 RUM. Initial 100 yard tests indicated the longer OAL, the more accurate they were. I tested 2 loads each with H-1000. 82.4g gave me a 1" group at 2785fps with an OAL=3.66" The 3 shots were spread out evenly horizontaly. The other load tested was 82.4g of H-1000 with an OAL of 3.67" Same thing, just seated out a touch farther. 2 shots were basically in same hole with a flyer about 1 inch away. The problem I run into is that 3.67" is about the max length they can be and just barely fit in the magazine. The bad part then is that every shot batters the tips and makes them flat. Even at 3.66" they do that. This is suppose to be Sierra's #1 accuracy load, according to them anyways. I was looking on accuratereloading.com and they use H-1000 with very impressive results. They are getting 3000+fps with sub 1/2" groups. Thats what I am looking for. One small problem I found was the difference in starting points for this particular bullet/powder combo. Sierra lists that 82.4g is the MAX load, while on accuratereloading, they start at around 84g and work there way up to like 92g for 3050fps or so. I just went with Sierra for now. I didn't get to extensive yet because I got in a bad car accident a week ago that totaled my truck. So am dealing with that right now. Just mainly looking for some feedback of others who have used the 220g SMK and the results you've got with what powders, etc. Thanks.