There is a thread over at the cast bullets association about some huge .400 bullets. Think barely not a 225 grain wadcutter.
They are looking for guys with 10mm revolvers to test some of these bullets. I told them I would post up a link on this forum.
https://www.castbulletassoc.org/forum/thread/who-has-40-s-w-or-10mm-revolvers/
Tell 'em sqlbullet sent you.