I was going to say .308 but figured the bastards would be on before I do anything more than club em.
I think that you need something light and handy, optical sights, and normal capacity (30 round) mags.
The MAC or any of the AR’s would serve, I guess, but I like the 124 grain bullet for short range work, along with the mutts for early warning, hence the MAC for walking...
The puppies come along just because they are.