I have been excitedly awaiting the return of my upper from GG&G for about 7 weeks, & I just got it a little bit ago today! I had them put on a fold down front sight & install my DSA free float tube while they had it. Problem is, now my bolt wont go into battery. It is stopping as soon as it reaches the barrel extension. The lugs look like they are lined up correctly, but I'm not an expert. So now what do I need to do? Help as I would love to shoot it tomorrow on my day off.

Take the bolt out of the carrier and slide the bolt carrier back into the receiver and see how the carrier key lines up with the end of the gas tube.

Maybe the gas tube is not aligned properly with the key??

Ok,.. so the bolt carrier key has a shinny edge like it's hitting against the gas tube. So How do I properly align it? I should have sent it with to GG&G but I didn't realize they wouldn't think to do a functions check after having the barrel off to install the free float tube.

I used a screwdriver to pry the gas tube a little in the right direction, & now I have it working perfect. I will go shoot it tomorrow, & once I have a successful live firing with no glitches it's off to Walter Birdsongs for a Green-T finish!

You want to have the gas tube to line up as straight as possible.  Any binding will accelerate the wear of the tube and erode the relief seal at the end leading to an eventual short stroke problem.

I would send it backe and have them make it right.  They screwed it up when they put the float tube on.

As long as the rest functions correctly I should be ok. When it goes off to Walter Birdsong for the Green-T finish, it will be completely disassembled, & then put back together in proper working order. I will only be shooting 100 rounds or so through it before I send it. That's to check the function of the Accuracy Speaks fire control group, & to get it sighted in to the new front sight GG&G put on.