Release triggers are used in trap and skeet for shooters who are prone to flinch and thus may stop or slow their swing causing a missed target. The release trigger has been found to be helpful in keeping shooters from flinching. Don't ask me how it does this, it just does. AFAIK, it has nothing to do with getting off rapid shots in sporting clays. A gunsmith usually has to install it, and the gun has to be clearly marked as having a releast trigger for liability reasons.