powderburns

There is a chance that Harvester sabots might make it easier to slide the sabot/bullet combination down the barrel. You won't know until you get some and try it. Harvester is recognized by most as the thinnest sabot.

http://www.claybusterwads.com/harvester.html

Harvester has a regular 50/44 sabot and they are now producing a 50/44 "crush rib" which is suppose to be even easier to get down tight barrels. I have not tried these yet so I can not confirm their advertisement. I do have some 50/45 sabots sitting on the table in the back that I am going to try as soon as I can.

Good luck