Release Triggers are normally found on Shotguns used for Trap. If you have never heard of one or felt one they can be extreamly dangerous.
Shortly after I started where I work we had a older Trapgun with a release trigger come in on trade one. The store manager, having shot a lot of trap, knew exactly what it was and individually set up the rest of the staff. He loaded a snap cap into the chamber and called each member over to "Try this Trigger". The rest of the Staff was off to the side and wasn't allowed to hear the conversation. He called each one up individually. {Most} Everyone got up there, the Manager ensuring the gun was pointed at the ground and pulled the trigger with nothing happening of course. They thought the trigger was broke and then released it with the corresponding hammer strike.
Now, having heard of release triggers at some time in the distant past (possibley from Unintended Conquenses) but never having shot one, I got up there and pulled the trigger with nothing happening. My mind went into overdrive computing the "malfunction" and the type of gun
. I got this sly smile on my face as I decided to try an experiment. I put the firearm in my shoulder, tracked it through an imaginary target and released the trigger as I swung through my imaginary target. Yep, a release trigger.
The Manager then gave everyone a "History" lesson on this type of trigger so that we could inform potential customers what it was. He came up to me after and said "I had a feeling you'd know what kind of trigger it was but wasn't really sure as rare as they are... that is why I called you last." Made me feel kind of good as most of the other Staff had been with the store for years.
They would take some getting use to but the concept, to me, seems reasonable.