I have the QR tings on a WInchester Apex muzzleloader and I tested the zero holding capability by shooting 4 shots with the scope mounted, took off teh scope, fired one with iron sights, then mounted the scope. All scoped shots clustered to a 1.25" group at 100 yds! I dont own a rifle that will do that with factory loads! Thoroughly impressive. Note: Load was three pellets of triple seven and a hornady XTP .45/300gr, in a 50 cal sabot. Scope was a Leupold VXII 1-4X20.