There are many reports of the factory rings slipping even though the factory screws are tightened to the point of stripping the allen heads.
Mine did.
I had one slip too.
My first T3 was a 270 WSM. I ran the supplied rings for a while and then went to put a Kahles on it, so I wanted to use Signature rings. I had no problems with that one, but didn't run it long using the factory mounts.
Roll forward few years and I picked up a 6.5x55. I started with the factory mounts, not being able to decide which aftermarket mounts to use, and the scope slipped. When I tried to take the mount off the base screw stripped out and I ended up cutting the base off with a dremel.
I'll never use T3 factory mounts again. It's just not worth 30-50 bucks, when most will have nearly a grand wrapped up in the rig.
