Heavy Barrel I have seven Burris FF2 's 2 3-9x40 1 3-9x50 and 4 4.5-14x42 and none of them show any distortion on the viewing edge maybe You need to send it back.
I have had a number of Burris scopes and still do, and also have never noticed distortion at the edges..but then again Im not looking to shoot stuff at the edges...