Major grouping problem?!

[Justhunt87]

I'm shooting a Ruger M77 17 hmr topped with a Luepold VX3 4-12x40mm. Took it out today to shoot it off the bench started out at 30yds just to get it close and was shooting 8-10 inch groups. So I took the scope off went and exchanged it for a new one put it on and it shoots the same. Checked rings everything is tight. Where do I start to find the problem? Thanks

 

[Creedmoor shooter]

Wow that is not good. What ammo are you using? Have you tried different ammo? I cant imagine any ammo shooting that bad though. Id make sure to check your action screws and make sure they are tight(but not too tight). Another thing you can do is contact Ruger about it and see about a replacement. Might have got a lemon.

 

[openlake]

Occams razor. Normally, the root cause of a problem that has the fewest assumptions is most often the correct version rather than the deeply complicated explanations Start basic and work into complicated. Assuming the rifle is a .17 hmr and you are using the correct ammo, something sounds terribly loose. Verify the scope rings are in the correct order front/back, are seated in the integral Ruger Base as well as the top/bottom scope ring screws. If not that, then the action screws are probably loose. If you have no luck there, make sure the gun is unloaded, and check the muzzle for a big ding. With 8 to 10" groups, something is major off, which makes it easier to find.

Let us know what you find. Good luck.