Powder Choices for Short Barrels
One of the neat things about QuickLoad is that you can get plots of pressure and velocity along the barrel. The velocity is highest when the pressure rises quickly and stays high for as long as possible. Start by looking at those plots for a few loads with powders of different burn rates.
You can then get some insight into muzzle pressure and velocity optimizations by looking at different powders and tracking the muzzle velocity and pressure.
I did this for a correspondent awhile back with the .223 Remington. I learned that it is indeed possible to get modest velocities with low muzzle pressures using fast burning powders.
It also appears that QuickLoad can help you select a handful of powder that give getter velocities in your short barrel than would be the case for loads optimized for standard-length barrels.
The flip side is that these better velocities come with the price of higher muzzle pressure. The backblast will be even more significant if you're sing a muzzle brake so be sure to wear plugs and muffs!