Quote Originally Posted by ballisticboy View Post
Videos which purport to show barrel harmonics are in the main very unconvincing. There are always important details of the experimental techniques missing many of which could be vital to a properly controlled experiment. They also miss the main point of any barrel movement and its effect on the pellet flight. Just because a barrel is vibrating it does not mean this will lead to an increase in dispersion, that will require a variability in the vibration which the videos do not show. Much of the barrel vibration shown will produce a bias in the mean point of impact not an increase in dispersion. The barrel harmonics will not have gross changes from shot to shot so should not produce large dispersion patterns. The difference in timing of pellet barrel exit is also too small to explain any large increase in dispersion due to barrel harmonics. There are other effects of the air pressure and pellet movement on barrels which can give rise to very high frequency barrel changes which affect pellet barrel fit and could lead to increases in dispersion but they are nothing to do with barrel harmonics.
I have said it before but really YouTube is not a good place to try to obtain accurate information on the science of shooting.
Agree with your sentiment regarding the difficulty in videoing because at relatively modest frame rates various parts of the image are captured at significantly different times. This means that a straight object which is moving relative to the camera scan pattern can appear to be bent - an effect I was startled to discover for myself when photographing aircraft with a stills camera which had a (crude) focal plane shutter. In the second linked video above the effect remains visible when filmed with different rifle orientations (wrt the scanning pattern of the camera) so I think that there is some attempt at removing that variable and I find it pretty convincing, although this does not mean that the effect is significant.