It depends on the conditions when used and then stored? If dry then it should be perfectly fine to keep it loaded for a period of time, mine was loaded for 2 weeks before firing and it worked fine with no effects (but it was dry and unfired!). If wet weather, high humidy or fired I would either shoot or dump the load clean as usual and then reload before your next use. With BP or subs always better to air on the side of caution!