[big boomer]

Well I can speak with knowledge of this subject I once fired a 44 mag that had been pushed into the case to far and just stuck out the top a little. I thought that my TC contender will handle anything but when I fired this load the pressure messed up the locking of my barrel to frame and now I will have to send in to get fixed. If you can break a contender just guess what it would do to a revolver.
I know you are talking about semi auto's but the results are the same.

[Deersniper]

If you are a reloader, make some dummy rounds without the primer and powder. Or, just buy some dummy rounds for 10.00. You can practice all you want with those. Even though they are dummies always point the gun where it can do no harm, and good groups.