No person shall shorten the barrel of a firearm or convert an imitation firearm into a firearm 6[or convert from any category of firearms mentioned in the Arms Rules, 2016 into any other category of firearms]
unless he holds in this behalf a licence issued in accordance with the provisions of this Act and the rules made thereunder.
Explanation.―In this section, the expression “imitation firearm” means anything which has the appearance of being a firearm, whether it is capable of discharging any shot, bullet or other missile or not.