I bought and 93r17 for my son for Christmas and the BSA sweet 17 scope. Had some rings for it and when I tried to mount the scope there wasn't enough adjustments on the scope tube. When I measure the mounting distance it measures 4.5 inches. When I put the rings on the mounts the distance is 4.25 inches. Needing information on what mounts I need to buy for the scope. Thanks for any information