I own a fine urban-warfare pair of firearms in the 40 S&W caliber: a Glock G22 and a Kel-Tec Sub-Rifle 2000 set up for G22 magazines. I can shoot the 40 S&W effectively to 75 meters with the carbine, and push it to 125 with some effectiveness.
The problem is the round itself, which can't be hotrodded much, or so most gunnies believe. The hottest versions of this round are plenty steamy, and the carbine would handle them just fine, but they are made with very fast-burning powders. This tells me that a 16.25" carbine barrel might actually slow them down from the speed from a pistol barrel.
I want to load up some 40 S&W with a slower powder which will gain me max results from the carbine barrel. I will be using 180-gr Hornady "Hornady Action Pistol" JHPs, of which I have a goodly supply. I propose using something like 2400 powder, but am open to suggestion. I will ONLY be shooting these rounds in the heavy-chamber carbine, and NOT in the unsupported-chambered Glock.