Dan Lowery has the correct butt plate screw.  So it and a correct stacking swivel & screw have been ordered.  While waiting for those to come in, I'll be cleaning/polishing the chamber.  I like to test feed / eject empty cartridges before even thinking about live ammunition (which I'm still debating with this rifle).  The cartridges on this one get sticky for the last 1/16 inch of travel before the rim seats.  I believe the binding is occurring where the neck steps down.