Been checking into this my self , apparently some makers in Germany didn't care for the disc strikers just more parts to deal with , also went to see a local gunsmith but he's 89 and in bad health so didn't get to talk long but when he was stationed in Germany he was a machinest in the armory , and they played around with wildcat rounds , he said we would load them Until we got a blown primer and the back down 12% and leave it , I asked him about the simson guns he said the officers would bring one in ever now and then , I asked about the groves in the action in the one I seen In Louisville , he said they were for a busted primer , in his opinion the Germans made the strongest actions . He thought I would be fine with a 405 or 450/400 as long as the work was good , and he said he would mill the groves 0.3 to 0.4 mm to the outside for safety in any rifle cartridge .,