The G2 Contender does take a multitude of barrels, from handgun lengths (nevermind legalities for now) to large centerfires. The frame will accept barrels made for the older Contenders as well as current G2 barrels. G2 barrels seem to have a protruding pin at the bottom of the lock-up area of the action which supposedly keeps one from using the newer G2 barrels on older Contender frames.
The rifle is sort of a hybrid mix of older Contender features and those of the Encore. It is slightly beefier than the older Contender but MUCH lighter than an Encore frame. I did a "guesstimate" picture of the G2 alongside and Encore - guess I should do the real thing. But here is that guesstimate:
Okay, here is the real thing: