Accuracy concern

[IRV WELLS]

I recently had a muzzle brake installed on a weatherby 300 mag. The accuracy has been greatly impared. I have checked the brake to assure it is tight, the scope and mounts are all tight. There is no evidence that the bullet is contacting the brake and there is no copper from the bullet around the barrel end as it enters the muzzle brake. Any thoughts of what i should look for? Thanks

 

[pearidge]

Irv, I saw one once where the smith who installed the brake, used a piloted 11 degree crowning tool to cut the crown obviously. And the pilot bushing was a little too tight. What actually happened was he rolled a burr just inside the muzzle on top of the rifling. Accuracy was destroyed to say the least. I got my hands on it, parted the burred part off, rethreaded, and reinstalled the brake. Shoots like a dream now. Could be a burr from a live center if he used one too..

 

[KenG]

make sure the muzzle break bore is concentric to rifle bore and not more than .020 to .030 oversized to your rifle bore. If it has any of these issues accuracy will suffer.