even disassembled it looks awfully familiar lol

Holy crap, it's the Quake II Hyperblaster

"The Model Type 971B (Authentic) is a heavy machine cannon that fires super heated energy slugs that can pierce even the toughest of Buildings and Heavy Cosmetics, though at the cost of being fired for 10 seconds to prevent overheating. With that said, the Authentic, other than rend both Buildings and Merc to slag, has also found success in the mining industry. Go figure."