GD short barrel is a +P round,and therefore not recommened for the Pup..
Now that being said,if one wants to use a certain ammo for the pup,and it digests it,I am not one to say do not use it..I just would not use much..
But remember +P is not recommended!!
The pressures that the +P generates on the Pup are not good for it..
When the GD SB rounds came out,we were pretty excited about it,untill we found out they were +P

I personally have not shot any +Ps in any of my Pups,as I have rounds that I figure are good enough for protection and feed 100%!!
Dberg,Welcome to the forum..