Problem with this is, that if short range fighter attempted to rush the sniper, he could just safely run away.
So if sniper is exploiting his range advantage, the short range fighter (lets say melee) should rush. In open space this means the sniper gets about 3 shots at you, which is survivable pretty much only by EN10 stonewall build. Anyway some sniper nerfing is planned or something so lets drop in, in closed quarters, it is usually snipers who are screwed (though only like 5% of fights are like that).
The problem is, that if the sniper takes 2 shots, sees he wasn't much successful, he can safely run away.
So I suggest you need full AP to be able to run and 1/3 AP to be able to walk.