The Mag Tech website lists their all brass shotshell hulls as being for large pistol primers. These are the same primers former Rem, Win etc all brass hulls used. They were successfully loaded with smokeless powder for years. The US Army issued a lot of these loaded with OO buck & using smokeless powder.
Large pistol primers may not prove reliable for igniting slow powders but work well for the fast to medium varieties. There is not a lot of pressure tested data about, but they definitely "CAN" be loaded with smokeless.
The MagTech hulls are of drawn brass construction, thus with thinner walls than the "Turned" cases from RM. This means they require oversize wads, the 12ga normally using 11ga wads, but it also makes them "Tremendously Less Expensive" than the turned ones. 11ga wads are readily available in card & fiber type.
My very first reloading experience was with all brass shells using smokeless powder loads which were still listed in the then current Lyman handbook. This was with the old Alcan/Fiocchi cases which were Berdan primed. I gave up on this because of the aggravation in removing the fired primer, which is not a problem with the pistol primer.
