My back up is kind of the opposite of what most people consider a BUG.
Instead of being a smaller, easily concealed gun in case I lose my primary or run out of ammo it is a larger and higher capacity gun that I can hopefully get to if I find myself in a situation where my primary is inadequate for one reason or another.
It is a Springfield XD-45acp which I keep locked in my truck safe.
With one 10 round mag and another 13 round mag it gives my a good amount of ammo before reloading.
