I took the muzzle brake off my Model 10-FCP-K a month ago for a local F-class match. At the time, I didn't notice much change in the zero, but I also changed box ammo at the same time, so I wasn't sure. I've been shooting Fusion 180 for a few weeks, zeroed without the brake. Last night I put the brake back on and went to the range this morning. It shot 4" high at 100 yards with no change (I think) but the brake.

I dialed down the zero and the resulting ammo grouped under 1", but with 1.1 mil change in zero. I think. I didn't have any tools to remove the brake and check it again.

Should I be surprised or is this just a result of the barrel vibrations changing when I changed the weight at the end of the barrel?

Joe