I tried one (B square I think) on my 30-30 win. I couldn't get used to holding my cheek off the comb and quit on it pretty quickly.
NOw that I think about it, I'm lefte eyed and maybe I should have tried using that eye. Also, on the mount I had, the attachment screws didn't seem very sturdy and I didn't trust it to hold tight. Have no idea what you're dealing with on the 71. Have one of those too but I'm pretty happy with the Lyman peep that's on it. 'Bout all I can say is give it a try if you have the mount and a spare scope.
Have you been following Brush Buster's m71 discussions here and on the reloading and cast bullet forums for GB? What loads do you use. BrushBuster has me back to playing with my 71 a little. May even try some 200 gr X bullets.