While I really like the FX Dreamline rifles I have other pcp rifles that will do the job as far as power, accuracy and shot count. What I don't have is a pcp rifle that will shoot slugs. Therefore I'm looking to get the new Impact MKII probably in .22 caliber for the relatively wider range of slug weights compared to the 25 caliber. Not sure as of yet to go with the 600mm barrel or 700mm barrel Impact as the cost difference is minimal. Now down to my question. I was on SPAW's website looking at the accessory slug barrel liners and see they list a slug barrel A and B. The FX pdf on barrel types I downloaded only lists slug liners type A in different lengths. Is FX now offering a different type twist or ID diameter slug liner. Thanks for any input. Bill