These groups were all fired by someone I consider to be an accomplished shooter, using an SR25, and match grade ammunition. They were fired on different days, with the groups using a muzzle-brake being fired on a calm day, and the groups fired "bare muzzle" being fired on a day with some slight wind, which the shooter says would account for roughly 0.25moa variance at a maximum.

The muzzle brake was a Surefire SR25 brake/SOCOM suppressor mount.

It appears that the brake causes not only fliers, but also a significant reduction in accuracy. I will post the flash-hider groups early next week. I am posting this both as a datapoint, and to generate discussion about the impact of accuracy that various muzzle devices have.

Bare Muzzle:


Muzzle Brake: