I was in a local gun shop the other day and was inquiring about shortening the barrel on a shotgun I own. I found out that they are really just a middleman and they send that type stuff off to a machinist. I told them I wanted it to be rethreaded to still accept remchokes and the guy at the store informed me that I might have to swap to a different type of choke. He said it has to do with how much metal is left when they cut the barrel to the desired length. I'm pretty sure it gets thicker as you get closer to the chamber. Does it sound like he is trying to get me to purchase a different brand of chokes or does he not know himself?