Well, the LeMat is all business with 9 44RB's and the 20 bore in the middle.
I do not foresee a problem for being loaded for a week.

If a slip of leather is place on the rifles nipples and the hammers of the rifle lowered on those overnight, just to seal the load,
they should be just fine. The greased (hopefully) patches will or should be sealing the tops of the loads.