Dave, I have 6 guns with the Hunter One Trigger from 1904-1950. I can't get any of them to the safe position after firing one barrel and it doesn't matter which barrel that I fire first. I have a 20 gauge Premier Skeet on my desk right now so I'll try to describe what I see. I think the issue is that the trigger action moves up as a unit to touch the seer to release the hammer. After firing the slide moves to the unfired side but the trigger action remains raised the slightest bit- not enough to engage the seer but enough that the vertical safety pin can't engage either. By pushing the trigger forward it allows the trigger action to set down fully on the assembly thereby allowing you to engage the safety. My guess is the guns that will return to safe after firing one barrel are worn in some fashion as the tolerance is pretty tight. Just my observation. Thanks, Tom