hi tango4n -
nice to meet you.
i have 243 ultra too.
to make my gun shoot good i had to:
1 - clean the gun carefully. use gunscrubber, or equiv, and get all the metal filings and gook out of the receiver and barrel hinge area.
2 - use light bullets, 52 - 75 grain or so, the heavy ones were fliers.
3 - remove the scope mount and clean the barrel and mount. mine had laquer or varnish under it that wasn't a uniform coating, only in some places. this may have caused the scope to move as the coating flaked off.
4 - put a small rubber O-Ring inside the forearm hole and just snug up the barrel screw.
the scope ended up being a moderately priced Simmon Pro-50. i like the scope, i've asked a few times about the simmons here but got no response. (a quiet way of being nice to me
)
was there a significant change in temperature between the days you shot ? or different loads maybe ?
sg