Lesson learned . I didn't want to believe they were *that* bad . Figured the deserved a fair shot (pun?) . I admit , I was wrong . Removed all the handy spare set screws and threw the dang blasted C-mounts in the garbage ! Not sure if the scope is still usable - severe wandering zero and nasty ring marks . I'll save that for another day.

Broke open a package of Accushot one piece medium mounts.Removed the scope from the AR15s GG&G rail .Optically centered it . Checked fitment of mount . Tightened it down ,added the weak link Tasco (not really its a WC+ 4-16),adjusted objective for 10m and fired a JSB at the target . 3.25" low dead centered ,repeat twice for posterity . Took it all back apart , bent the barrel ala floor and reinstalled it . 1.25" low dead center, repeat twice for posterity. Removed scope and mount. Dimpled scope rail stop pin hole w/ 1/8" drill bit , added two drops of LocTite to the hole and reinstalled the mount and scope .

Ding! Ding! Winner !! 2 shots to sight in , 5 JSB's into .2" c-t-c at 10m . Will continue to repeat for posterity until either the scope breaks or I am satisfied .  I know the predatory feral feline wasn't very impressed...   

Mod.34?

"More thankful=less cranky!"

The m40 , or a 34 by any other name is still a dressed up 34 . I actually got about 40-50 pellets through it when the groups started opening up . Checked all the screws,patch through the barrel gave no improvement . Then I'd get a flyer 2-3 inches out of the group , next group would be where the flyer's poi was...then the other direction ...then ...I got the tools out again ! The $15 Accushot mount is surprisingly stout .  It found a home.

It sounds a lot like some groups I get when I'm fatigued,although I realize that was not the cause of your situation.Those 34's and derivatives(40's,Panthers)are very accurate guns, but also unforgiving.If I do my part, they will do theirs, EVERY time!

"More thankful=less cranky!"

Agreed. First warm day in a while here and oh boy the groups came squeezing tighter than ever. Went from 1" @ 30 yards (cold days) to dimes @ 30 yards (today) if I'm being good. Now I can actually get to learning to shoot the thing seeing the groups are no longer so random.

Not sure you have to take it down to 10 ft lbs but dropping it by a few would make a big difference.

"but I'll be needin' that gun, fer squirrels and such."

I don't need to make it a 10 fpe gun just yet . . I've done too many things to it already, I'm going to shoot it awhile now before doing anymore.

Was that the post by Marcelo ? I'm saving that one , it's a good'n.

but the  40-50 pellets were over two days time and it was the only one of the 3 airguns being shot. Still , it could be fatigue . Just doesn't explain why the groups tightened back up immediately after swapping mount/scopes . I dug the rings back out of the trash anyway - too much of a packrat .
So far so good with the newer set up , needs more pellets through it before I can say "it's solved" .