I bought my mother a new T/C Omega X7 for this past Ohio muzzleloader season. I cleaned it thoroughly before ever shooting it. Couldn't get the factory protectant out of the barrel. Solvent, soap, you name it, couldn't get a clean patch... Finally got it "clean enough". When she went to shoot T/C super glide shockwaves... mom couldn't get them more than three inches down the barrel. I could "force" them down, but with way more force than should be necessary. I kept using the supplied No. 13 cleaner, trying to condition the barrel (it should have had a good amount in the metal from the pre-cleaning ritual) in hopes of making them slide easy enough for mom to shoot confidently. After 10 rounds of forcing sabots and cleaning between shots, they still weren't going down any easier. I switched to my Barnes Expander MZ's (that are tackdrivers out of my Lyman GPH 50 cal). No better... she couldn't get them down the barrel. I then went to some Hornady XTP sabots... still couldn't get them down the barrel without two handing the rod with all her strength.
I'm now pissed. I've owned two T/C hawkens with no problems. I wanted the X7 to work because it was the right length of pull for her, but she can't get a sabot down the barrel on her own... ridiculous.
I resorted to powerbelts because of the different design. I don't like them personally but I figured her slightly undersized barrel might seal the powerbelts more effectively. Sure enough, she could seat a powerbelt with no problems. The X7 cloverleafs the 250 grainers at 50 yards.
I also switched solvents and went with my Butch's Black Powder Bore Shine which I use in my Lyman and love. This didn't change the tightness either.
Still can't get the patches to come clean between shots. I'm in the same boat with you, so your not alone. I've been shooting traditional bp rifles for years with no problems. This is the first in-line I've dealt with. I know T/C makes quality guns and barrels, so I don't think I have an undersized barrel.
I would appreciate any inputs that could resolve this problem from the experts on this forum.