The Ecore makes more sence for big bore rifle, because the Contender frame won`t handle the presure. I have a Contender in .17 AH though that has been my main carry gun for about 4 years now. I made my own fore arm for it because it was just to lite. I push a 19 grn. bullet at 3,600 fps. and the gun shoots point blank to abt. 290 yrds. I bought a .204 barrel for one of my Encore frames, but will still carry the .17 AH alot because it is so lite and shoot so good.