[Nostrafus]

Well if you want to go for magnets, use what are called Rare Earth Magnets, they come in all sizes, and can even be found in very very tiny form, the only problem is you have to slide the weapon off, you pretty much can't lift one without breaking your model. They last a few years before their magnetic field goes dead, and are pretty cheap. Let me give you an example of how powerful they are, when two rare earth ring magnets with the same polarity aligned together are put in close proximity, they can hover about 2" apart when kept steady (on a wooden dowel.) And the ring magnets can weigh close to 1 Lb.