Semi
I used my 25 acp breech plug in my encore same as your omega I had no hang fires and good groups. I use 209's in it just because I don't have to reprime. The 25 acp I used with T7 because of crud ring. I agree that long flash hole is causing yor problems. The 209 may cure it as you will get a hotter longer flame also run a wire or needle through the channel and some hoppies no 9 it disolves the carbon better. I also use a 1/8 th drill bit by hand in the larger primer port. I will only shoot BH209 in my for encore for hunting now. It is just that much better. I use Pinacle for fun shooting and 209 with win or federal primers shooting. If you waht a 25 acp breech plug for your omega let me know I have 3 of them.