I do appreciate how strong the magnets are. The force between a two 1cm square steel plates in a 2T field is about 159N or 36 lbs of force.

I do not think the contact area between parts of the trigger / sear etc and striker / whatever else are more than 1cm square, they’re also lubricated. Given the orientation of the pistol could also change, making the friction force less effective, I think it’s possible that a pistol is able to fire after being sucked into the MRI.