Could a loose muzzle brake mess up my groups?

[sambo3006]

I did some shooting this morning with my usually very consistent half moa Hart barreled 7STW. The groups were not as small as usual and really opened up on the last group. I noticed that my muzzle brake was about a half revolution loose at the end of my shooting session. These groups were shot at 100 yds with no wind and a very steady rest so no shooter error there (no more than usual). Just wondering if the loose brake could have messed up the barrel harmonics and opened up my groups?

 

[highridge1]

yes

 

[Rocky Mountain]

Another yes!

 

[RT2506]

Ever see those tunable breaks on the Browning rifles. Same principle with having a loose brake. It makes your barrel out of tune and it will play sour notes.