I have a 28" ported barrel for my mossberg 500 and was wondering if anybody had noticed on thiers that there is a slight increase in the barrels diameter towards the muzzle. It's very slight but every once in a while if the light caught it right I thought it looked like the barrel bulged a little bit right after the ports, but it looks like from there on the barrel is that thickness. Maybe it's a little thicker right there to give space to cut the choke tube threads? I have nothing to compare it to so I figured I'd check here.