As a hinged front trigger is wider than a standared trigger blade,I can see several problems in trying to fit one to an existing gun. I am not saying it can not be done ,but it will be a pricey job to do. What I have done in the past is to file the front trigger blade to allow it to go further forwards. THe trigger spring holding it against the sear as normal . This may not be possible on all guns and the amount of movement will be limeted, but if it is, then it will give you the same effect as a hinged trigger.
