One of my rifles is wearing gas tubes excessively. I started having trouble with the rifle cycling and cleaned it to find the end of the gas tube all chewed up and a small mark on the gas key.

I replaced the gas tube thinking it had a defect from the start and began hitting the gas key. Now about 200 rounds later I’m seeing a little abnormal wear on the end of the gas tube again, nothing like before but I have never noticed wear on a gas tube at all on any of my rifles.

I’m using an Aero upper, American defense bcg, pri gas buster charging handle, superlative arms gas block that was adjusted per their directions, rainier ultramatch barrel that was pre dimpled for the gas block so I feel that alignment should be good. And a diamondhead vrst keymod Rail.

My initial thought is that the rifle length gas tube is allowing some play? But I’m not sure if that’s correct since the hole in the upper should support the tube even though it’s not really stabilized by the barrel but or rail. Any thoughts or suggestions? I’m thinking of switching to an aero enhanced upper and their rail that goes with it but I hate to do that and it be something else that could have been fixed with less $$. Any suggestions are welcome, thanks

I've had a couple that were binding up a little when I put them together.
If it's the way I'm imagining it, take your upper off the lower and take the charging handle out.
Put the BCG in and slide it in until you can tell where it's hitting on the gas key.
I've had to bend the gas tubes to get them to where it's smooth when running it in and out.
If you had a picture of what you're having issues with it would help.

If you are sure it's not misaligned, check first that it is not bottoming out inside the key. If not that check the gas hole is open all the way and not bent and catching the tube.

I've run into this before when the gas block has been a little off center, enough for the gas key to chew up the tube.  Since you put a 2nd tube on it with the same issue, guessing your gas block is 1/64's or so off center.  It doesn't take a lot.  Bending the tube is another solution.  Do you have to dial extra left or right to center the irons on this gun?