Gas tube too long?

I put together my first upper and the bolt won't go all the way home. I fiddled with it a bit and pulled a bcg from a different commercially made upper and it had the same problem. Then I tried both BCGs in the commercial upper and they went right in. I looked closer at the one I put together and the gas tube extends a good half inch beyond the spot in the receiver where the commercial upper gas tube ends. So clearly there is an issue with the gas tube length or positioning.

The barrel is a 16 inch wilson combat that is spec'd for a midlength gas system and I orrdered a "Steiner" brand mid length gas tube from Midway and installed it. I don't think I installed it wrong because it is roll pinned in the gas block and the gas block is positioned close to the "hump" in the middle of the barrel and one of the screw in pins on the gas block hits a dimple in the barrel put there by the manufacturer. So did I do something wrong in assembly? Did I get an out of spec gas line/ Something else? Thought I was home free and now I am pulling my hair out trying to figure out what I did wrong.

Never mind, I am just touched in the head. Put the gas block on backward.