I suggest to edit your OP with info such as this just so that newcomers to this thread don't need to ask again or need to search through the pages for it.
I also would like to know how many rounds would be fired in each "session", or course, or I mean, in a given shooting drill. Is it 46 shotgun rounds in a single drill? I don't think they make shell carriers that big!

The point being, how many mags to be required in each shooting drill, how many shot shells (how big of carrier will I need...lol), etc? Obviously with 5 or 10 round mags, then you need either 12 or 6 (at least) of them if the course had us shooting 61 rounds in one "run". Obviously I suspect that the rounds are actually broken up into different stages etc.
So, just also put up there how many mags we might need, how many shot shells we would need to carry, etc.
Newb here...just trying to make sense of it and help other newbs.