A friend of mine has a nice litle shooting range on his grounds that allows us to sight in our rifles up to 200 metres.

Right in front of the fixed bench he has set up a line of 10 cartyres, so that the muzzle of the rifle sticks well into the centre hole of first tyre.
This acts as a silencer and completely muffles the sharp bang. A hundred metres away from the target in any direction and you can't relate the noise to a gunshot. The only thing you hear is the bullet hitting the target (I didn't try to listen behind the target!)

My question is if such a setup would infuence accuracy in any way?

That wouldn't effect accuracy. It's actually a pretty good idea and one that I may apply to my own range. My neighbors might appreciate not hearing my 458 Lott.

The only thing I don't like about it would be that 10 car tires would be a bit unsightly in my yard. Maybe I'll come up with a cart to mount them on so I can wheel them to the barn when I'm done shooting.

There will not be that much sound suppression with supersonic bullets.