Shots in a horizontal string!

[7x57]

This past Saturday I wanted to run a few rounds down the tube on my STW and was suprised to see a consistant horizontal grouping of an inch or so. This rifle has never shot like this before. Was a .5 MOA shooter with the same load from previous year. By the way this is what I'm shooting; Savage 116 action, Pac-Nor 30" SS Super Match in 7mm STW, Sharp Shooter Supply trigger and lug. Action bedded and barrel free floating in a laminated Boyds stock. Winchester brass, Fed. 215 GM, 81.0 grs. of H-1000, and Horn. 162 A-Max. Anybody out there have any idea what might be causing this.

 

[tbeasley]

are u using the same powder as last year?
Make sure your seating die didn't move any and check the bullets, sometimes manufactures machines change slightly and thus the bullets could be shorter or longer.
Are you shooting the same ammo that u made last year or the same ammo from the box you used last year? just trying to clear up some info.

let us know

 

[7x57]

The only change in the load is bullets. Same bullets just a different lot#.

 

[squirrelduster]

I had the same problem with my 300 win mag. and it was my grip.
I was too rigid and hanging on too tight causing the problem myself. It was very difficult to believe I wasn't perfect. Have someone else shoot it that you know is very accurate and see if the results are the same.
Do you have a muzzle brake?

 

[7x57]

Yes, I had Pac-Nor install one of their brakes.