Dave is right of course, you don't have to have a wad between the charge and bullet. I do get more consistant shot to shot accuracy using a wad with increased powder charges without a leading problem.
What type of powder are you using? You will only need between 70 and 85 grains of powder for those bullets. I use 80 grains 777 FFFG and that bullet as my back-up elk load, will shoot under 2" in my Huntsman at 100 yards w/peep sight. I use a fiber gasket wad between the charge and bullet. The White Super Slug (obsolete) will shoot under 1-1/2", same powder and rifle and what I used on the little 5x5 in the avatar.
The QLA (false muzzle) on the T/C might not allow you to shoot very accurate and consistant with conicals. Just the cold hard facts, unless you get lucky. Most of the QLA's are not concentric with the bores and cause havoc with accuracy.
I use the Sagebrush wads, .060 50 cal.=.518 dia ~ Item# S-26518. Just push one down between the charge and bullet. Others use felt wads, both lubed and unlubed.
Scroll down the page about 1/3 of the way to:
Over Powder Wads ~ 1000 per package
Vegetable fiber gasket material engineered to resist high heat & compression and water resistant. These wads are precision die cut to be over- sized in each caliber for better bullet base protection and sealing gases. Below are the most common sizes available in .030” & .060” thick. Other sizes may be available. Call for more information..030 38-55 cal.=.386 dia ~ Item# S-23386
.030 40 cal.=.416 dia ~ Item# S-23416
.030 45 cal.=.462 dia ~ Item# S-23462
.030 50 cal.=.518 dia ~ Item# S-23518
.060 38-55 cal.=.386 dia ~ Item# S-26386
.060 40 cal.=.416 dia ~ Item# S-26416
.060 45 cal.=.462 dia ~ Item# S-26462
.060 50 cal.=.518 dia ~ Item# S-26518 Any Size $19.99 SPECIAL! $17.99
http://www.sagebrushproducts.com/ShootingProducts.htm