Re: "Yes. BECAUSE of the police, which can be turned against the population"
There's an international treaty governing de-militarization of (and trade in) big guns. IIRC, the procedure for most field artillery and tank guns was to fire a .50 BMG or 20mm round through the barrel transversely to render it unusable.
To 'fix' that you'd need to fill the hole and clean up the rifling, and probably also heat-shrink or braze a reinforcing sleeve onto the outside of the barrel. No idea how accurate it would be.
Biting the hand that feeds IT
