Is this normal grain?

I was under the impression that the d5100 has pretty good high iso results. I may be wrong but whenever i shoot at more than 200 the images look grainy. I'm hoping that someone can help. This shot was taken at; f5.6 1/640 iso 400 lens 55-300mm @ 300mm

Way out at 300 and the aperture probably have something to do with it...if you call that grain let me show you something! LOL

I promise you the D5100 punches way above it's weight class...

Not a good capture to really judge, lens at it's limit, small subject, possibly not in focus. I have not noticed grain issues with the D5100. The only way I even notice any noise is blown up to 20x30 or on HDR's over 16x20.

With the 55-300 all the way out, I don't understand why you had to shoot at 1/640th. Should have been down to about 1/320th at the most. And why f5.6? Would have been better at f8. And lastly, why shoot in broad daylight at ISO 400? Would have been better at ISO 100. It's just not necessary to shoot at high ISO's in broad daylight. Just because the camera is capable of high ISO doesn't mean you HAVE to.

I agree with the no need for high ISO and the other thing I have noticed on my 300mm lens is if I stretch it out to 300mm I get grain. Not sure if it more sensitive to vibrations or I am just twisting the lens barrel (figuratively speaking).
But if I shorten up just a tad to 280mm it is less grainy.
Crop or zoom in on the bird which is the focal point and see how grainy it is instead of judging the depth of field looking grainy.

at 300mm on a wide ranging zoom, image quality isnt going to be stella at best. F8 would be the peak here.
I dont see too much grain here, its rather more not nice bokeh. I think it would be ambitious too, zooming in on the bird, even if it
had been shot on a D800, considering its so tiny in the picture. Your problem here was simple really.
the bird was simply out of range for your lens. The bird is so tiny in the picture I doubt it would fill the screen at 100%.
When shooting things so small, you still need to be fairly close to get a decent pic even with a 300mm.

Thank you all for your answers. Seems I'm gonna have to try this again. This time with a little more info. Thanks again.