Worked up to the loads we used in the .22-250. All showed round holes in the target. Also got some good groups, just wanted to get a little more velocity for the fun of it. We didn't have the chrono along when testing the loads so don't have exact figures. I would bet we were way under 4700 fps, but over 4100. Loaded 20 rounds for a one-time try. This is not recommended for a standard load.
I agree that this could be a problem with casual/careless loaders, but we were aware of what could happen and were watching for any abnormalities.