I have been working with the owner of a local fishery over the past 3 years gathering evidence of cormorant damage. This year I have been granted a license from Natural England to shoot a number of these birds.
The license has a number of conditions which I am not prepared to breach as I want it renewed again for next year.
One condition causing problems is that the birds can only be shot when they land in the water & not when in flight. I have been using 42 gram size 3 shot, 3 1/2 inch magnum 12g. But as the birds sit so low in the water and their feathers are so tight when not in flight and the distance means the shots don't seem be be having any effect. The birds will continue diving and fishing just out of range. Although advice on the license recommends shot size 3-4 & 12g,it doesn't state this must be used. I won't use my .22 rim fire as the bullet would skim off the water surface and I have no suitable back stop if that happens. - so here's the question does the .17 HMR behave like the .22 for bouncing off all sorts of surface or would it break up / penetrate the water?
The maximum height I can achieve is lying on top of a shipping container shooting at a distance 10-100 yards so a variety of angles which the bullet could hit the water at.