The trigger finger bolt release I was using is a Phase 5 . They take a regular bolt release and weld a steel arm on it because most 308 actions are so heavy ,there is no room to clamp the BAD type on .I have these on another side charger 308 and a 6.5 creedmoor and they work fine .They are noticeably heavier than just the bolt stop on its own .Im guessing because of the weight ,it cant move fast enough to operate . I recently bought a Tubbs weight to add to the carrier that's supposed to slow the cycling down .I haven't had time to try it out yet.