casdad,
I have a .45 Knight Disc 6-7 yrs old.It's always been with any sabot or powder load I've ever tryed - extremely tight.

I did perform a procedure that slightly improved the condition but that is the way they are designed - Tight.

I s/w a Knight rep for about 30 mins after purchasing the gun.He stated in no uncertain terms it is one reason why the gun is so accurate.It is very accurate! I Couldn't ask for much more.

Matter of fact Knight turned me on to Clean Shot(now APP).That's another topic.

A freind just purchased a .50 Knight and has the same issue.Very accurate but extremely tight loading. I carry back up Power Belts(slip fit) for a 3rd shot as after 3rd round sabot is damn near impossible to load up without damage to bullet or field swabbing.I was surprised how accurate the power belts were and took a deer with one outa that gun.

Have a .50 T/C Thunder Hawk.Bought in 94.Antique by todays standards but desiged to shoot sabots.I tryed 2 sabots and didn't like the tight fit which really wasn't tight,I was simply used to loading conicals in a CVA side Lock.

I ended up going with T/C conicals,worked up load with FF BP which was very accurate/effective - took alot of deer with that gun - along with my nephew that dropped a nice buck with it.

Anyway - I've never changed that load until last week when I went to APP and PR sabots.