For what it's worth, Chantry is also right about availability. Magtech hulls are out-of-stock in all the usual places. The search continues.
Sometimes you can find the old brass hulls at gun shows. Most of them used the #57 primer (if my memory is accurate) and a large pistol primer can be used in place of the #57.
Downside is that some brass hulls may have some sort of different primer and used hulls may not chamber in your shotgun.
The thin brass Magtech and antique can be re-sized. Used RMC are a real bastard to re-size. A 1 ton arbor press isn't always successful.
