LOL. They don't get thicker as they sit around. The stainless steel doesn't absorb moisture and swell up.
Originally Posted by BiNumber3
A small bore barrel can cause problems with a level 10 bolt due to it having a wider tip. The recommended minimum size barrel bore to use with a level 10 bolt is 0.685".
Another potential problem is if the outside of the barrel is slightly smaller diameter. This can cause the barrel to sometimes get pushed off center by the twist lock assembly. If this happens, then the bolt will rub on one side of the barrel and prevent operation. You can correct this one by wrapping some tape around the back of the barrel to artificially make it bigger so that it stays properly centered. Do it in two locations(forward and back) so that you don't get barrel wobble.
Except for the Automag in front, its usually the man behind the equipment that counts.