140-150 bar reg and a decent bit of HST should get you to 900-910 fps. Since you got a Tac compact, you aren’t going to get a ton of shots. Probably best to listen to qball and just use the hades and shoot them around 850fps.
I believe I was at 865 with that pellet. It's .22 now, but I'm switching it back to .25 this weekend. I'll check and let you know what the fps is thereafter. I sure do love the DTC!