CMMG Car-Sear Excursion with the tab bent a little ahead adequate to time it properly so trigger can only be pulled once the bolt is *Nearly* shut. The timing is extremely picky and also the tab needs to be bent precisely so the trigger can still be pulled (but with https://frttriggers97528.webbuzzfeed.com/35871307/the-2-minute-rule-for-rare-breed-trigger