The MB Bee is a improved version, bee brass is very thin, I've never worked with the MB Bee however I did have a 17 Bee years ago while fire forming virgin brass id loose about 20% of the cases, I had the win bee back then so had access to once fired cases when using the once fired cases I'd lose over 50%, I've fire formed thousands of AI cases in over a dozen cartridge offerings I loose maybe 2 or 3 % of those cases, I didn't have a annealer so that changes things, I'm going to say this falls under the category of nothing ventured nothing gained, I'm getting ready to load up for a day or two of trout fishing should return Thursday perhaps friday, I'll sort out enough brass for you to get serious with at least a box maybe two, when I get off my but and sell mine nobody will know what I had anyway, few things are more frustrating than a gun you can't get ammo or brass for.