I'll be glad to clear this up.
The problem was fixed by epoxy-bedding the action, and replacing the sighting system. Here's what I found when doing this job:
The action has two cylindrical lugs attached to it, that the stock screws go into.
The stock has two round holes that the lugs fit into. The front lug acts as a recoil lug, and it's screw pulls the action down into a close fitting hole in the stock. The rear lug has no front to back contact to speak of, but instead is pulled down to snug the rear of the action into the inletting.
I discovered that the front lug, the recoil lug fit fairly well, and the action's fit to the stock there was very good. It got the epoxy treatment but only a very thin layer of epoxy remained after the action was clamped down upon it and was allowed to cure. I put epoxy on the rear side and bottom of the hole only, to facilitate removal of the action.
I clamped the action into the stock for bedding with black electrical tape, several layers pulled tight, fore and aft as close to the lugs as I could get it.
The rear lug had a problem. The first application of epoxy placed in the bottom of the round vertical hole for it was untouched after it was allowed to cure and the action was removed. A second application below the rear lug finally ended up touching the lug, providing support below it and to the rear. (Ahead of the rear lug is the trigger spring, don't want epoxy on that!)
So, as the gun came, tightening the rear screw would flex the action, and still provide no support there. The hole was too deep, or the lug too short, however which way you might prefer to describe that situation... It took approximately 1/8 inch of epoxy to give the rear lug something solid to tighten down upon and give it a point of support without pulling down unnecessarily upon the action. - I believe this was the root of the problem, and I probably could have addressed it just as well with a stack of washers as I did with the epoxy.
Stock pillars would be a great idea for this stock and action. - It still may get this treatment someday.
After bedding the action as described above, I bought new Leupold vertically split aluminum rings and a Nikon P-223 4-12x40 scope. This combination of actions fixed the problem and on the next outing, five shots went into .170" (center to center) at 50 yards.
I guess I ought to mention the load:
Hornady brass, Hornady 68 grain BTHP bullets, CCI BR-4 small rifle benchrest primers, 24.5 grains H4895 has the powder kissing the base of the bullet.
COAL 2.317" put the bullet .019" off of the lands. No crimp was used.
Note that I had to file a 'V" notch in the inside front of the magazine so that these bullets would feed properly at this length. - The noses were hanging up.
Anyway, it's behaving itself much better now. That's the main thing.
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