Dram Equivalent is the velocity of a shot charge that would equal the velocity given with a load of "X" drams of blackpowder.
12 GAUGE
Shot weight - Dram Equivalent - Shot Velocity
--------------------------------------------------------------------------------------
1 Ounce - 2 3/4 - 1,200 FPS
1 Ounce - 3 - 1,255 FPS
1 Ounce - 3 1/4 - 1,290 FPS
1 1/8 Ounce - 2 1/2 - 1,090 FPS
1 1/8 Ounce - 2 3/4 - 1,145 FPS
1 1/8 Ounce - 3 - 1,200 FPS
1 1/8 Ounce - Heavy - 1,250 FPS
1 1/8 Ounce - 3 1/4 - 1,255 FPS
1 1/8 Ounce - 3 1/2 - 1,310 FPS
1 1/4 Ounce - 3 1/4 - 1,220 FPS
1 1/4 Ounce - 3 1/2 - 1,275 FPS
1 1/4 Ounce - 3 3/4 - 1,330 FPS
1 3/8 Ounce - 3 1/2 - 1,240 FPS
1 3/8 Ounce - 3 3/4 - 1,295 FPS
1 3/8 Ounce - 4 - 1,350 FPS
1 1/2 Ounce - 3 1/4 - 1,150 FPS
1 1/2 Ounce - 3 1/2 - 1,205 FPS
1 1/2 Ounce - 3 3/4 - 1,260 FPS
1 1/2 Ounce - 4 - 1,315 FPS
1 5/8 Ounce - 3 1/4 - 1,115 FPS
12 GAUGE continued
Shot Weight - Dram Equivalent - Shot Velocity
--------------------------------------------------------------------------------------
1 5/8 Ounce - 4 - 1,280 FPS
1 5/8 Ounce - 4 1/4 - 1,335 FPS
1 3/4 Ounce - 4 - 1,245 FPS
1 7/8 Ounce - 3 3/4 - 1,155 FPS
2 Ounces - 3 3/4 - 1,120 FPS
I know this isn't complete, I'm still working on it.
Just because a DE is listed here, it does not mean that it is safe for any gun.