I first started using X bullets in the early '90s, the 100 grain in a B78 .25-06. I consistently got 3/4" or slightly better 5 shot groups, and performance on deer and antelope was great. I only recovered one bullet, it weighed 99.8 grains after going from just behind and below the right kidney to the base of the skull, including shattering 6" of spine.
I then used the 150 grain in a Browning 1885 7mmMag. Accuracy ~1"/5shots, again, no problems with performance. Only recovery was from an antelope shot stem to stern; the bullet knicke the pelvis and turned base first. The base actually punched through the hide but the expanded petals caught it. Weight 149.7 grains.
I then tried them in a M700 8mmMag, both the 200 and 220 grain bullets. Accuracy was abysmal, around 6". I shot 2 elk with that rifle, with 200 gr. Hot Core bullets, but at close range they expanded too violently. It wasn't until the TSX came out that I used it again, they have been a great improvement.
