That Leopold scope appears to have a fairly long tube. You should be okay with two-piece bases. I had to go with semi-rail on the Springfield because the Nikon 3-9x I bought had a short tube. At first I had extended ring on front with two piece bases but when I added optional iron sights, I wanted quick detach rings and nobody makes them extended. So it was either switch to a rail or a different scope or put up with improper eye relief with scope too far forward ( = poor acquisition and/or messed up field of view). Note where the front ring is located: almost touching the bell for objective lens. Full field of view just makes it. The forward ring is locked into the last ring slot available in the base before loading cutout. That Nikon scope is a dandy but tube is very short. The discontinued very low Weaver 1-piece base on my 98 Mauser has only two ring slots. Short tube scopes could be a problem as having only two slots on the rail limits options for ring placement. But the low power Bushnell I selected has no objective lens bell so I knew I had nothing to worry about. Eye relief would be dictated by my needs not the base(s) and rings.