Since I'm a former Glock owner I will sometimes pull the trigger to get the slide off. Lately I usually use the sear deactivation lever unless I don't have anything handy to push the lever down. There's always the frame tool but that's a whole different story. I always check, double check & triple check my chamber & mag well to make sure that the M&Ps are totally & completely empty before pulling the trigger for a dry fire.

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Former USN, Retired US Army