I think it is possible. Depending on the angle at which the pistol struck the housing, the magenetic force was pulling it one direction, and the impact (sudden stop) allowed it to contiue in different direction. Remember that an object in motion tends to stay in motion, so internal part will still move after the frame and slide had been stopped. There are validated cases in which ferrous objects have been drawn into the core at 40MPH. That's pretty darn fast with a lot of momentum. There was a case where a 6 year old boy was killed when an oxegyn cylinder was brought into the room and it struck him when drawn in.
Here is some interesting info from a
Radiology Today article:
Metal Drawn to the Magnet
Missile effects is the term generally used to describe the way MR’s high-powered magnet pulls some metallic objects into its field. The Valhalla case—where an emergency oxygen tank was drawn with such velocity and force that it killed the young boy in the bore—is the most horrific incident to be picked up by the popular press, but similar, nonfatal occurrences happen fairly regularly around the country.
Routine patient screening before scanning is intended to prevent such problems, but when imaging centers power down their systems, they regularly report finding paper clips, pens, keys, staples, and an array of other magnetized items in the bore. While technologists usually worry most about these small objects distorting scanning, it’s also important to realize that an MRI magnet can pull a stray hairpin across the room at 40 miles per hour.1 In fact, Gilk cites a case where “an MRI patient needed to have a bobby pin surgically removed from their nasal cavity when the pin was drawn towards the center of the bore [while] the patient was lying head-in in the scanner.�
As if that instance is not serious enough, hemostats, scissors, wheelchairs, patient gurneys, intravenous poles, and defibrillators have all been turned into projectiles capable of severe harm. When nonmedical people enter the magnet room, things can get even worse. In one instance, a police officer’s gun discharged as it was sucked out of his grip; in another, a firefighter was trapped and nearly suffocated as he was drawn into the bore when the breathing apparatus strapped to his back became magnetized in the MRI room. Only slightly less dangerous—because the people involved managed to escape injury—are several documented incidents involving mop buckets, vacuum cleaners, toolboxes, and other everyday items.2
Force Fields
The phenomenon by which metal becomes spontaneously magnetized is ferromagnetism, which affects iron, nickel, cobalt, and many other familiar metals and alloys. Although most implants today are made with titanium or other nonferromagnetic metals, it’s common knowledge that MRI systems can affect older angio and cerebral clips, bone pins, dental work, and even some tattoo dyes. That’s the key reason patients are screened. What’s less recognized is how MRI scanners may interfere with devices such as pacemakers, pulse oximeters, automated defibrillators, cardiac monitors, insulin pumps, cochlear implants, and vagus and other neurological stimulators.
Many people believe MRI radio frequency (RF) shielding acts like the lead shielding in a CT room, keeping the hazard trapped in the scanning room, “but that’s not the case,� says Gilk. “MRI interacts with its own space, and the spaces around it, in a way that’s entirely different.� Where a CT installation’s lead shielding is designed to keep radiation inside, MRI shielding keeps stray radiowaves out. “The focus is on protecting the magnet from interference, not the other way around,� says Gilk.
Plate steel is the only physical material that can contain an MRI system’s magnetic field. “The lines of force penetrate brick, wood, concrete, cement—which means that not only people outside the MRI suite but even people and machines outside the building can be affected,� Gilk explains. “Any steel in the building construction reshapes the magnetic fields in the MRI, and MRI magnetizes the steel in the building. So the levels of complexity are several orders of magnitude greater than a CT, even though they may not look all that different on the floor plan.�
Current designs using plate shielding, however, usually are not equipped to deal with the newest crop of 3 Tesla (3T) commercially available systems—and even higher-powered research magnets. Compare, for example, the typical few millimeters of steel plate with the 14-inch–thick, 500-ton shielding New York University recently installed around its new 7T whole-body scanning system. Gilk likens the result of inadequate shielding to swimming in a lake during a thunderstorm: “Steel is to magnetic force as water is to electricity—it offers a more efficient conductor.�
