If your gun will place itself in battery when a magazine is inserted you really NEED to have it fixed. Any gun that will do this is running right on the ragged edge of not locking back when you want it to or locking back with rounds remaining in the magazine. It's not a "cool" feature although many people think it is. It is a mechanical defect. There is also no need to slam a magazine in with any more force than what is necessary to seat and lock it. The lips can be damaged and cracked and so can the ejector. The reason for the mags having a magnetic charge could be from a pallet of new magazines being picked up and set down repeatedly with a large electric forklift.