Bergara 300 WM HMR Accuracy Issues

[ktm131rob]

All,

First time post on this site, I have been reading alot on here and I have gotten alot of good info.

I have a 300 WM HMR i got it new this spring, seemed to shoot ok around 1 MOA with factory I tightened that up with some load work to around .5 - .7 and for what it is I was happy. When I shot those groups I had a surefire brake on it, I since switched it out to a Dead Air Key Mo Brake. I took the rifle our to verify zero and I could only group 1.25, chocked it up to a bad day behind the gun. Today it was 1.5 inch groups. I verified it was not me as I shot repeated back to back groups with my 6.5 cm in between at .5 inch.

My question is could I have overtightened or screwed up my groupings with the muzzle brake I installed? I didn't use a torque wrench and to time it correct I had to apply some leverage.

Any other suggestions with this rifle that may help it?

Thanks,

Rob

 

[ShooterVaughn]

How many rounds have you shot through it and have you cleaned it since? Iv heard with these rifles that after 180 rounds the groups open up.

 

[moosemeat]

ShooterVaugh- it's when dirty, every barrel is differnt.
Ktm131rob- I would seriously doubt it. It may have changed the harmonics of the barrel and you might have to work up a new load.