I've had an old Weaver, Steel K-4 on mine for 14 Years. Reasonably priced, and they take the recoil. I've thought about replacing it, but it ain't broken, so why fix it. Old K-6 might be a little better, but the deer I've shot with it or should I say the Mossberg 500, K-4, Remington Sabot's combo, havn't noticed the diff. Longest shot has been about 110 yards. This year I plan to try the newer (1900 fps ) slugs. Havn't yet because I had a supply of the old Rems which work just fine. With the increased velocity and range, and demminshing eyesight, a little more power may be in order.