I have tried the 25 ACP on both Omega and Encore and will give you my opinion. If you shoot BP, Pyro, or T7, then the 25ACP will ELIMINATE blowback into the action and I think it bought me some accuracy in the Omega, didn't notice anything in the Encore. If you are going to use any of those propellants, definitely recommend them. The Omega was doing a pretty solid 1/2 MOA for the original owner and then me on that system; .25acp, 3F T7 81 gr weighed out and Barnes 245 Spitfire bullets. The Encore was never quite that good, but a consistent 1 MOA with many loads either 209 or .25acp. Neither rifle worked well with the .25acp and Blackhorn 209 powder due to weak ignition. I won't use any powder other than BH209 now so tolerate a bit of non-corrosive blowback with regular 209s just to get the benefit of Blackhorn powder. I sold one of my .25 plugs and am hanging on to the other just in case a new powder comes out that works with it. My recommendation is to try BH209 with CCI 209 primers first. I shoot that powder just like my centerfires, have put 30+ rounds down the tube, no swabbing and same POI as the 2cd round on all the rest and left the gun fouled and not cleaned since Oct 29 till now with no issues (shot it once in mid Nov just to confirm after hunting in the freezing rain for 2 days and again last week to kill a doe).