The hole in the middle is the same diameter and threads on the screws on the trigger bow.Tony Beck wrote: ↑Fri May 09, 2025 9:19 pm Quick way to tell if they are armory, are the threads #10, 11 or 12-26? Springfield liked 26 TPI, but it is decidedly non-standard today. Internal lock screw are #10, The lock plate through the stock screws are #11 (0.2" diameter) and the barrel tang screw is #12. Try threading one of those screws into the plate. Don't force it if it doesn't want to go. Also, the thread angle is 55 degrees instead of today's 60 degrees, but modern threads will fit with a little drag.
The hole that’s closer to the rear of the trigger bow is a smaller diameter hole.