You should have no problem leaving the same ammo in your Mags for 6 months to a year.

Someone I know actually shot a magazine full of .45 Auto ammo that was loaded in the Mag during WWII. All the rounds went bang and the Mag actually fed them all after over 65 years. That's an extreme case but I've hear of that happening many times.

__________________
Freedom is never free!!
SWCA #3437