Some people dont game with their guns, some people who join this site are not always from Canada, so they can play in places that may not have a higher FPS limit.
You want the most push for FPS. Personally, Id redo the whole top of the mechbox and front end. New tightbore barrel, systema 1 piece hopup with sleeve and nubbin, personally I enjoy the deep fire airseal nozzle, and would go with a systema cylinder head, and a piston and piston head of your liking, me I went with systema red polycarb and duracon head. Slap in whatever spring of your liking as well. The spring guide is alright looking and seems solid. So it should hold up to atleast an m120 without problems probly higher too, but if your running something strong like an m150, you may want to consider changing the gears, motor and battery as well.
"Its only a little bit on fire"