I am not an expert. I know that Buffalo Bore carries this ammo. Whether they load it or not I do not know. Texas Ammo used to carry this ammo at a fair price, but has gone out of business after 10 years. Triton used to load 45 Super as well-I have a box of 20 165gr hp. They went out of business two years ago if I remember correctly.
45 Super runs at 28,000psi and has a stronger case thn your normal 45 ammo.
Buffalo Bore carries 185, 200 and 230gr hp and 230gr fmj.
For more info on the 45 Super go to
http://glocktalk.com
then go to Gun-Related Club Forums, then down to The Big Dawgs Club.
The moderator there, Turbonatr has shot 45 Super out of his G-21C with a 22lb spring for a few years. There is a sticky there all about 45 Super including velocity and energy for each (185gr through 230gr). It is the most info I have seen so far on the Super. He would be the person to ask, unless someone here has also loaded this round and shot it extensively. This round is really for the re-loader, because it is expensive at $39.00 per box of 50.
But for the occational use at the range and a carry load on the trail, I think it makes a good alternative to the 10mm. Hope this helps.