The weaver type rail is the only mount I've seen. You may be able to have a smith mount a couple standard leupold or burris dovetail bases on the barrel using some of the existing mounting holes and adding a new one or 2. But doing that you are going to limit mounting options due to the short ring span. Some of the older Bushnell low power variables are light weight, I have a couple 2-8x32 Scopechiefs that are as nice as my Leupold Compact 2-7x28. Other than a fixed power, those are the only light weight scopes I have experience with, but I'm sure there are a few out there.