I just got MP's 525 gr, 2 cavity, brass, hollow base, diablo shape, shotgun slug. It looks like Lyman's giant "pellet" molt but it's a full bore size being over .730 at its forward driving band. I'll have to play with what wad to use. I plan to coat it with Hi-Tek bullet coating, as I do with most of my bullets. (I love that stuff)
So how is the mold? Well, as you've read others write here, it's just about perfect. There are no scratches or flaws. The deep yellow brass is blemish-free, inside and out. The interior cuts have no machine marks of any kind. The sprue plate fits flush and with the correct amount of tension. It fits firmly but not overly tight. Where the pins for the hollow base pins fit through the blocks, they align perfectly and do not bind in any way. This will allow the slugs to eject easily from the blocks and drop off the hollow base plugs. The mold blocks fit together perfectly without any sign of an air gap. I can't see any light through them when held up to a bright light. The Lee-style handles I use fit perfectly with good but not sloppy movement. I'm likely to drill it to take my mold temp probe.
It doesn't matter if you take into consideration what this mold cost, it was about $115.00 shipped from freakin' Slovenia and it got here in really good time, two weeks? This is a really, really, nice mold. I'm not sure what else could be done to improve it.
The next step is to clean them really well and get any contaminants off them. A lot of folks like to season their molds by heating them and then letting them cool a half a dozen times or so. I've never done that. I've never done that but I've only had a couple of other brass molds before. Of course, they turned out fine and produce bullets like crazy. In fact, I really don't have many problematic molds.