Can the Mossberg 590M shoot the mini-magshells in the large magazines without
problems?

If you want the shells to feed reliably out of the tube, you'll want to get one of these. Without it the shells will tend to tumble sideways and jam up. I have one for my 500. It works

Ignore my last post. Just realized you're talking about the magazine fed model. Sorry about that still early, and not enough coffee

No problem, I understand. I am aware of the insert to make the fit.
Just wanted to see if anybody is using it on the magazine fed model.

Thanks anyway.

I own this gun, and while I don't have any direct experience with that ammunition, my opinion is a strong enough no that I would not buy a box of that ammunition to try it.

I guess you could get away with one as the +1 round, before attaching the magazine, or by feeding them one at a time, without a magazine.

I am trying to understand any advantage for using that round, as you can't get any more shells into the box magazine.

This is a place that I have to point to the manufacturers recommendation.

From here: https://www.mossberg.com/service//owners-manuals/

An afterthought based on others' comments: you also want to look for star-crimped rather than roll-crimped shotshells. The tolerance of the length is fairly tight in the box magazine, and I have heard of them jamming. Again, I have no direct experience with this, YMMV.

Thanks. That's the answer. Appreciate it.