I have had problems with the STD mounts with rear base screw coming loose. The gun 300 Wthby had been shot all spring and summer in 90 deg weather and I took it to Wyoming for a Elk Hunt where it was freezing. After missing an Elk at about 300 yards I took it behind camp to a makeshift base and was 2 ft off the target. The windage screw had loosened. If I had to do it over again I would use a dual dovetail base on any hard recoiling rifle or use a Gentry,conetrol type ring because they are impossible to screw up. I have never had the windage screw come loose on either of my 2 300 wsm's but I never have taken them hunting in freezing weather either.