I'm a first time builder here and I've run into a snag. I'm building an Aero M5 (308). It looks like for normal ARs the rear takedown detent and spring go through the back of the receiver and the end plate is supposed to hold it in place, but with the M5 the detent channel actually goes down to the grip. Aero included a small set screw to keep from yeeting out my spring. Unfortunately I can't quite get the spring compressed enough to get the screw started.

Since the detent just retains the takedown pin is there any harm to trimming it a little bit? If that's really a bad idea are there any easier ways to get this set screw in?

The spring is likely long enough to use without the screw so it may be necessary to shorten the spring by an amount equal to the length of the screw.

This.