Blagg- that does look a bit short- with dry snow (sorry, no pics), my 2310 shoots snow a good 60 feet. A couple of things you might check out:
1. Is that a used blower? I've found that the clearance between the fan and the housing, if increased due to bent blades (yeah, rocks-- I got a ton of 'em!), makes a huge difference with throwing distance. My Toro walk-behind would suffer with only 1/8" additional space between the edge of the fan blade and the circular housing. I finally replaced the fan on the Toro, after heating & pounding it back into shape a couple of times- photos are of its original fan. It's hard to see, but my 2360 blower, still pretty new, has only about 1/8" max clearance.
2. I'm sure they knew what they were doing when it was designed, but your discharge chute seems awfully long/tall compared to others I've seen. Perhaps more "drag" in there?
3. Not sure how this applies to your set-up, but my front (mid, really) PTO on the 2310 runs at 2000 rpm; the rear runs at 540....??