Some numbers from the 777 powder sight.

Pellet 100 gr 240 XTP 1801 fps
Powder FFG 100 gr 240 XTP 1883 fps
Powder FFFG 100 gr 240 XTP 1927 fps

All are "100 gr" and the pellet is the least powerful. Hope that helps with your understanding. Check the Hodgon sight for more numbers.