I have both systems for my Omega; however based on the sound of a rifle primer vs the 209 I would doubt that a bullet would come out of the barrel with the rifle primer, it only makes a little pop noise. The 209 sounds like a hot 22. I'm not sure what this would prove. I do know that the 209 primer with 777 and a 348gr powerbelt only lets me shoot one shot without a swab between shots and the same set-up with the .25ACP and a normal rifle primer allows at least three shots without a swab between shots. I am liking the .25ACP conversion a lot!!!!