Hi, all -
After suffering through some consistently below-average chronograph readings (with several bullet/powder combinations), I've begun to think that my barrel might be a little tired. I bought the gun (a Sako AV in 7mm mag) used a few months ago.
Today I "slugged" the barrel -- I drove a bullet through from muzzle to breech. The outer diameter remained unchanged at .284" and the inner went to .280". This is exactly half the reduction I thought I'd see, as I was told in hunter safety training that grooves are usually .004" deep.
So, I ask the rifle mavens here...does it sound like my barrel is worn out? I'm really at a loss to explain the lower velocities I've been getting, but before I decide to invest in a new barrel, I'd like to make sure that this one truly is bad. Thanks for any input.