You are going to have a hard time holding steady at 300 mm DX (450 mm equivalent on FX) and that shutter speed. General rule of thumb is to keep your exposure speed at the reciprocal of the focal length. You can push it a little slower with VR on but not too far.

In this case if you had bumped the ISO to 800 your shutter speed would have been fast enough to prevent motion shake. Your D3100 will give good results at ISO 800, don't be afraid to use it if needed.

working on it in Middle TN
Nikon D3100
18-55 mm Nikkor VR
55-200 mm Nikkor VR
55-300 mm Nikkor VR
150-500 mm Sigma OS

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