I have been talking to Al Minneman at MTM about the need for a box that will hold 45/70 etc cartridges BASE DOWN or the same thing-BULLET UP. I fear that my Dacron shifts or cream of wheat mixes with the powder when I use a base UP box. I haven't found a box that will hold 45/70 cartridges base down.
The MTM 100 round 30/06 size case has a black insert. I suggest that another insert would hold maybe 60 or 70 45/70, 45/90, 40/65 and ????? cartridges base down. 
If you also feel the need for this type box, why not contact Al at
allenm@mtmcase-gard.com

Thanks;
joe b.