A number of manufacturers are interested in the .45 GAP cartridge, but they were waiting to see if major ammunition makers would add it to their lines. Now that this is the case, some interesting introduction may happen at the end of this year, or more likely, at the SHOT Show early next year.
Why the .45 GAP? Is it just another superfluous cartridge? Not from the gun designer's point of view. The shorter overall length requires less slide travel then the .45 ACP, and in a compact pistol this can be important.
Because of very short recoil spring tunnels and slide travel issues an ultra-short .45 ACP can have reliability problems, and a wider grip (front to back) is required vs, the ,45 GAP.