Yeh its very nice i cant see anything wrong with it at all, only thing to change is add hypernurbs to the stock ( perhaps a phong tag too ) and maybe change the trigger, apart from thats it 9.9/10.
But mate tone down the colour of the render, kinda hurts your eyes to look at in lol.
Its an alright model, but I think you need to work on areas which are round a little more. Such as the back sholder suport and the handle. They seem very gritty and badly modelled. This could be done so much better to corispond with how well the front of the weapon is done.