Even with a smaller gun body (and a short barrel), you still have to account for a hopper and a tank. In addition to my T9, I sling mounted an SP1 with a Qloader and a 45/4500 tank. The direct mounted qloader seemed perfect. But, the tank still kept it awkardly hanging.
Thats the most aggravating thing for me going from tac shooting to scenario paintball. X-ball im fine with the tank, but everything im comfy with in tac shooting gets botched by the tank.