I had a bunch of .25 slugs in many weights and dia (.249, .250, 253, .254. But one I had, NSA .249 29gr were as accurate as the JSB 33.95's at 50 yards. I didn't have a chance to go farther as I was at a range I don't normally go to on an errand. Yours may be different and there was also a 15-23 mph wind. Since I was pressed for time I shot them pretty fast. The groups aren't as good as it will do but as soon as I had sight picture I squeezed the shots. I will chrony later to see what speed I was shooting but I actually turned it down a bit from the 970 fps a few clicks.. I'll post what I find but they were consistent at even at the higher speed. I was just trying to see if a little slower would still group to save a bit of air and they did.