I think it is a bit of a toss up on those two Leupolds. I have a 1.5-5 and like it. The 32mm objective on the other one will give you better low light performance and probably a wider field of view. I have a Weaver 2.5x with post reticule on my 35Rem. I think anything much over 4x on these rifles is overkill, but if you twisted my arm I think I'd go with the 1.5-5x. Just a little "cleaner" looking on a lever gun in my opinion.
Mounts are very personal. I like Weaver and Talley style. Have had poor experiences on two Burris/Redfield twist in style.The Leupold QRW rings and bases give good repeatability taking the scope on and off. The Talleys repeat well if you get the rings with the levers and are a little narrower.
