the main problem in trying to accurately diagnose, the most likely source of most problems, posted on the internet forums.
is that your totally dependent on info ,you can,t personally verify and a great deal of the info you need,
is either not specified nor is most of it, accurate.
I've repeatedly found a great deal of the problems posted are the result of both improper component parts like scope mounts, or rings,
installation and a failure of the guys posting to even understand fully the questions asked.
I've had lots of the local guys having problems resolved with a careful dis-assembly, cleaning and careful re-assembly.
loose scope mounts, defective scopes, loose or overly tight action screws badly bedded rifles, and badly fouled bores are common.