ok this is weird to me i have to frame older type that takes screwdriver to select rimfire or centerfire. and a newer frame easy open with fire selector on hammer just got a 17 hmr barrel today and put it on my older frame fliped the hammer to rimfire nothing ?had a .44 barrel on that frame that shot perfect thought i might have the selector wrong spun it around nothing put the .44 back on and boom! put the 17 on my new model frame and it worked put the 17 back on my old frame and nothing got to lookn at it the bar inside is not falling down to let the hammer go foward with the 17 ,but works with all my other barrels. and the 17 works on my newer frame?