I have owned Contenders since the early 70s in just about every configuration they can be had in. Handguns, rifles big and small. Right now most of mine are setup as carbine length varmint rifles. I have some high end custom barrels and some factory barrels, all of which shoot very well.

All breakaction guns require slightly different methods for handloading and gun set up....its inherent to the design. The more you know about them the better they will do what you want.

Among others I have -
MGM .204 Ruger SS 23" full bull
VVCG 6mm 30-30 AI 23" full bull
Bullberry .221 FB 16 1/2"

Factory barrels in
.223
.204
.357 Max
7-30 Waters
44 mag

this one is the .204 MGM ready for a day of pds at 350-400 yds.