Hello AB,
My suggestion to you is to try all the basic checks:
Is the scope mounting system tight, no loose fasteners?
Is the rifle securely attached to the stock, meaning all screws tightened properly at the right torque?
Have you checked if the barrel is truly floated, by slipping a business card under the barrel, between the stock all the way to the receiver?
Can you verify that the crown of the barrel has not been damaged?
Usually, a horizontal grouping might mean flinching and/or anticipation from the shooter. You might get one of your friends, a good shooter try it out to see if the problem follows the rifle.
Another possibility is as follows: the scope might be damaged. Try the box test:
Always pointing the scope at the center of the target, dot or diamond, bring scope adjustment up 10 cm, left 10 cm. Shoot as if trying to get the best group possible, with 3 rounds.
Adjust right 20 cm, then shoot again as said above.
Adjust down 20 cm, then shoot again as said above.
Adjust left 20 cm, then shoot again as said above, and
Adjust up 10 cm, right 10 cm, then shoot again as said above.
If the scope is good, you should end up where you were pointing at.
Hope this long-winded explanation helps, let us know.
Phil aka tazzman
