interchangeable

No. Impact and wildcat barrels are different, and gen 1 wildcat did not have the liner system.

Actually this is not correct, certainly not for the last two generations. The barrels in the Wildcat and Impact (MK 2 and M3) are identical. What is different is the shroud. I have often swapped Wildcat and Impact barrels (for example, where I have a .22 Wildcat barrel but not a .25, or where I have a 500mm for one but not for the other) by simply switching the shrouds. In fact, I recently purchased 500mm and 600mm shrouds from FX USA for my Impacts so that I could make use of my Wildcat and Dreamline barrels in different calibers and lengths. And yes, Dreamline (Not the SuperLight barrels) will also interchange.

Chris
 
No. Impact and wildcat barrels are different, and gen 1 wildcat did not have the liner system.

Actually this is not correct, certainly not for the last two generations. The barrels in the Wildcat and Impact (MK 2 and M3) are identical. What is different is the shroud. I have often swapped Wildcat and Impact barrels (for example, where I have a .22 Wildcat barrel but not a .25, or where I have a 500mm for one but not for the other) by simply switching the shrouds. In fact, I recently purchased 500mm and 600mm shrouds from FX USA for my Impacts so that I could make use of my Wildcat and Dreamline barrels in different calibers and lengths. And yes, Dreamline (Not the SuperLight barrels) will also interchange.

Chris

This is correct for the newer models. Wildcat mk1 and mk2 have different barrels to the impact. The mk2 does have the liner system though, so it can be upgraded to superior liners. 
 
No. Impact and wildcat barrels are different, and gen 1 wildcat did not have the liner system.

Actually this is not correct, certainly not for the last two generations. The barrels in the Wildcat and Impact (MK 2 and M3) are identical. What is different is the shroud. I have often swapped Wildcat and Impact barrels (for example, where I have a .22 Wildcat barrel but not a .25, or where I have a 500mm for one but not for the other) by simply switching the shrouds. In fact, I recently purchased 500mm and 600mm shrouds from FX USA for my Impacts so that I could make use of my Wildcat and Dreamline barrels in different calibers and lengths. And yes, Dreamline (Not the SuperLight barrels) will also interchange.

Chris

This is correct for the newer models. Wildcat mk1 and mk2 have different barrels to the impact. The mk2 does have the liner system though, so it can be upgraded to superior liners.

Thanks for the clarification. I was referring to the last two generations of Impact, and the Wildcat MK3 and Dreamline. I don't have any experience with the Mk1 and 2 Wildcats.