Well I think my problem is solved. I got the new 1" tube the other day, and I don't have any more leaks out the bottom of the carto. The other m1a1 I have is the 1.5" prototype. It looks like the screw is a little larger in diameter and it keeps the seal better. No leaks at all so far after a day or two.
Also, was the material for the tube changed? I ask because I have a crack in the prototype tube. It doesn't leak out of that crack, but it looks a little unsightly.
Let me be perfectly clear... I am not asking for a replacement. I know it was a prototype to test, so I don't mind paying to help out with r&d
I am just making sure that there is a difference and I'm not just crazy 
Also, was the material for the tube changed? I ask because I have a crack in the prototype tube. It doesn't leak out of that crack, but it looks a little unsightly.
Let me be perfectly clear... I am not asking for a replacement. I know it was a prototype to test, so I don't mind paying to help out with r&d