A former firearms student of mine texted me that he has a dozen boxes or so of Speer 200gr. for sale.
He also used a term, they are of 45 gap made exclusively for the glock 45,37,38 and 39. And, the Springfield EMP 45.
Does anyone know what he’s talking about? Is this just regular 45 ammo? I’ve claimed to be the Jarvis/Vision of firearms, I’m always looking to learn. 
Well that answers that. So they made a very specific ammo just for a few specific firearms. I did not know that. Thanks Jerzy.
The .45 GAP has the same diameter as the .45 ACP pistol cartridge but is slightly shorter, and uses a small-pistol primer instead of the large-pistol primer most commonly used in .45 ACP ammunition. Originally, the maximum bullet weight of the .45 GAP was 200 grains (13 g). In order to provide terminal ballistics that matched the standard 230-grain (15 g) .45 ACP loads, the .45 GAP was designed to operate at a higher standard pressure—roughly equivalent to the higher pressures found in .45 ACP “+P” rounds. Since the .45 GAP has a much smaller cartridge volume than the .45 ACP, the desired pressure and resulting velocity needed to be achieved through powder selection alone. Later development concluded that the .45 GAP could also fire 230-grain (15 g) projectiles, as does the .45 ACP; though this pushes the .45 GAP cartridge to its limits.
You are welcome…
There are so many different ammo sizes that I had to think for a minute to find out this one…
It just find it amazing that companies try/tried to make their firearms so proprietary that there certain odd calibers would only work in them.
I have a stupid little Beretta Tomcat, that uses a .32acp… and that was always darn hard to try and find any ammo for it when I used to shoot it. At cabelas, there’d be like 15 feet of shelving dedicated to 9m and 40 and they’d maybe have 3 boxes of .32ACP.
Being able to somewhat standardize is also a + on a battlefield, being able to use your ammo with a picked up firearm or vice versa.
The .45 GAP (Glock Automatic Pistol) was a solution in search of a problem. The intent was .45 acp performance in a 9mm size pistol. It was a rousing failure. While it worked ok (as expected of a Glock). Most .45 folks just stayed with the ACP. Ammo was/is rare and tended to be pricey. Wasn’t around and being marketed long.,
LOVE this thread! Thanks for the great info!
Damn! I love learning new things and I was never aware of this myself! Thanks Jerzy! Great info.
Happy to help ! 
Thanks @Jerzees and @Jeff-A1 brothers you guys are some knowledgeable people. I learn new things from you guys everyday. 
Actually all thanks should go to @Fizbin , he was the one who brought this ammo to our attention.
I realize this topic is about a year old, but I would like to make a comment almost in favor of what was almost a good idea. There was great info on the .45GAP offered, but the reason for the cartridge is an interesting one. Many agencies were using .45ACP, and more than a few individuals were not able to grip high capacity .45ACP weapons comfortably. The .45GAP grip could be made a little more manageable since the cartridge was a tad shorter. On paper that looks like the perfect answer. In reality most agencies would apparently prefer to change to a proven weapon/caliber.
This caught my attention because a Glock 38 was offered to me at a nice price. Owning it would probably be more costly and difficult than buying it.
The only benefit for me with the .45 GAP would be if I were reloading it.
I heard it (the .45 GAP) described as “a solution looking for a problem”. 
Google can be of help.
