My .260 just doesn't get projectiles out as fast as some of the numbers I've seen on 24HC...
I can only get 3,150 to 3,180 from 100's out of a 21 1/2" tube. Others quote speeds from 3300 to 3350 with 100's with like powders I use.
In my tube, if I could get to 2900 with 120's and 2800 with 130's I'd probably be happy...