I couldn't get the GMX to group worth a crap out of a Rem 700 30-06. The target I was shooting them at was a paper target stapled to a piece of cardboard. The cardboard was held vertical by some pieces of wood that were attached to a piece of 2x12 about 18 inches long, backstop was a large old-growth stump. After firing one string of the GMX, I went down to check the target and found 2 of the bullets sitting on the piece of 2x12. Perfectly mushroomed, with the pedals intact. There was very little of the dirt and wood detritus that should have been on them from impacting the lowest area on the stump. I don't know how they ended up sitting on the wood, but their terrible grouping with several different powders and loads, and the weirdness of finding the spent bullets on the wood, turned me off them.
Now, Amax are a WHOLE other story. The 168gr shoot better than the 168gr MatchKings in all the 30 cal rifles I've tried them out of