Hey everyone. First time poster here. I recently purchased an AUG A3, and when I was breaking it down the first time, I noticed something about the barrel that concerned me. When glancing down the barrel from the muzzle end, I notice a slash or cut that runs in opposition to the barrels rifling pattern. I do believe it is at the spot where the gas piston is, so I imagine it's the vent for the gas, but I've been told by several folks that it doesn't look normal. I'm wondering, should it just be a tapped hole, and not a slot/slash?