Other than doing it just for fun, I really don't see the purpose of having a long range rifle painted.
I can understand a shotgun for turkey hunters - turkeys have great eyesight, and they generally can come in very close where a camoed shotgun is actually a great benefit.
I can kinda see a muzzleloader being painted because deer, although they don't have great eyesight, can come in relatively close.
However, on high velocity rifle cartridges, where shots are generally going to average 100 yards, I seriously doubt that there is any benefit to having a camo rifle.
Again, if anyone wants it painted just for fun, or just to look cool, then that's great, but I don't think that anyone can say that he/she shot a deer at 100 yards and part of that successful hunt was because the gun was camoed.
Zachary