How exactly do you tweak a gun? And what sort of gun that will kill bears ain't gonna kill a wolf? And I am not sure that wolves stampede.
Simple example: there are a number of guns that can be converted from semi-automatic to full-automatic with very simple changes, removing a spring, filing something down, etc. If you've got a pack of wolves coming at you the rate of fire could certainly change the balance in your favor.
It seems like we are getting into further trouble here. As this pack of wolves is stampeding (never heard of wolves stampeding, though) at you, removing the spring, filing something down might not be consistent with the very short period of time you have as this herd (?) of wolves is closing the gap on your, er, person.