My guess is big bore ammo.Rated the most i seen in fps.
1. Item 24A/20 (+p+) 115gr. Jacketed Hollow Point
Browning Hi Power MK111, 4.6 inch barrel---------1426 fps
Beretta 92F, 4.9 inch barrel-----------------------------1402 fps
Glock 19, 4.0 inch barrel--------------------------------1389 fps
2. Item 24B/20 (+p+) 124gr. Jacketed Hollow Point
Browning Hi Power MK111, 4.6 inch barrel------------1330 fps
Beretta 92F, 4.9 inch barrel-------------------------------1304 fps
Glock 19, 4 inch barrel------------------------------------1296 fps
3. Item 24C/20 (+p+) 147gr. Jacketed Hollow Point
Browning Hi Power MK111, 4.6 inch barrel----------1179 fps
Beretta 92F, 4.9 inch barrel------------------------------1131 fps
Glock 19, 4.0 inch barrel---------------------------------1165 fps