I've messed around with both 12ga. and .410 in the magtech brass shotshells.
For the 12 ga, I got the RCBS die for loading the brass cases.Those require that you have a removable bushing, they're 1-¼ diameter. It comes with a shell holder that works for holding the brass while it's being primed with large PISTOL primers. It also resizes the case AND has the ability to put a crimp on the mouth.
Since the brass case walls are so thin, you can't use any of the one piece plastic wads. The powder would get by the gas seal, AND the gas seal won't expand to seal the hot gases.
The use of 11 ga paper and fiber wads makes that problem go away, but the card wad is notorious for not being a good sealer of hot powder gases. BP sells a over-powder-gas-seal called the X12X. It's over-bore for 12 ga, so it seals the brass cases quite well.
The .410 has the same problem. There's no quick fix like the X12X for the .410. What I did is make a wad punch out of an old 44 mag case, sharpened the mouth and drilled the primer pocket to make oversized .429 wads. I cut them from 20 ga. card wads just for the over powder wads. I used standard .410 fiber wads and over shot wads from there up.
For the .410, a shell holder that fits the 300 magnum, also fits the .410 brass. So you can use a universal decapper die like the lee to push out the primers, large PISTOL, and a hand primer or your press mounted set-up to re-prime. Now, you may want to crimp those shells. I ran the shells up into a 7 mag FL sizer with the decapper/expander removed. The beginning of the shoulder turns the mouth of the case in like a champ, creating a nice crimp.
It takes some work, and thinking outside the box, but you can go shooting with something that will start conversations with fellow shooters. They also work quite well.