so the Saint Edge series has two different lowers. Springfield did not cheap out and actually designed two different lowers, if you look at the edge rifle back behind the the rear takedown pin. You will see that there are QD holes machined into the lower. On the Saint pistol they got rid of that. And now your trigger is not a chassis version, if you google Timney AR trigger thats what the Saint Edge pistol should look like. (as far as I know, mayyyyyybe there was a weird version?) maybe the gunstore Created a “special edition?”. I got pretty **** close to one of the first ones available and it had it. Plus I have taken enough apart that they all have had it. I would say if you are happy and like the trigger that should count for more. The allen head screws are there to make sure the pins dont work their way out during shooting. The chassis style triggers are self contained and have sleeve style pins that are hollow that hold the trigger and hammer. Then you insert the pins into the sleeves.