Did a test on pellet port vs slug port velocity comparison With the pellet port at the setting previously shared, .22 cal Fx hybrid slugs left the barrel at an average of 936.8fps. Flipped the barrel over and shot 5 through the slug port. Average was 953. Slug port shots had an extreme spread of 18 fps. Pellet port shots had a spread of 3fps.
At 25 and 50 yards accuracy was very good with both ports, The slug port might have been slightly more accurate. I intend to boost the speed up to 953 with the pellet port and see if I can keep the extreme spreads low and gain some accuracy.
Having said that, I shot a 10 shot group 100 yards with the pellet port.

I will be happy If I can eliminate the flyer. I did spray the slugs with silicone spray but now need to weigh and maybe gauge or measure and see if that helps.