Well, you could go on Safari and hunt cape buffalo with it! Or, go to Alaska and hunt Grizzly bears! That would be fun my boy!
There is really no use for a 9mm carbine since it is too powerful for home defense because of penetration. You really can't shoot much over twenty yards with any kind of stopping power.
The only thing it has going for it is that if you can't hit the a bull in the ahs with a bass fiddle with a pistol then you might manage to hit the bad guy with a rifle. Ammunition cost is the only other recommendation and you can plink cheaper with a .22LR rifle.
