This is just gonna be a quick PSA on my friends brand new upper. Call it a test of customer service at this point.
Here's the scoop. He wanted a piston upper, we both looked and researched and decided to go with  Adams Arms, factory pinned 16" middy upper. He bought it from western sports online, they have a very nice selction of AA uppers if anyone is interested. It was purchased with a DD piston Omega rail installed already and the A2 flash hider.
He had an armorer friend build up a spikes stripped lower he already had, Unknown LPK was used. the lower looks nice with moe grip and BAD lever installed. Carbine buffer, m4 stock .. looks like everyone else's

When he first got it and attached to his lower, he went out and wanted to run a few rounds through it to function test it. He has been waiting on his sights for so long. He had the upper for a soild 2 months b4 he could fork up the cash on the set of BUIS he wanted. He goes to chamber a round, and it wouldn't chamber. so he extracts it no problem, chambers another, it does fine and fires. next round fails to chamber. these are HANDLOADS. Niether one of us have ever had a problem in 3 different AR's with these handloads mind you. So he tries some factory stuff.. no problems, each one chambers easily. He only shot it 2 or 3 times. He goes and buys a small base die set, problem solved. All his handloads now using the SB dies chamber fine, so maybe just a chamber reamed on the small side of sammi.

Fast forward, open sights installed we go out to get him zeroed. gun is lubed with some rem oil, dry teflon stuff, maybe not the most recommended stuff out there but freshly lubed..
first shot, bang* & then click.. inspect chamber didnt feed a round. At this point he was using a metal 20 rd colt mag. pull CH back and chamber again. bang* check target, *bang, check target *& click.. again didnt chamber a round.
We did adjustments to his sights while firing, I was certain it was that older magazine... we switched out to a new 30 round Pmag.
Same problem, sluggish ejection, won't lock back on the last round fired.. not once. tried a Pmag from my gun.. same thing. We took his lower off his gun I had 2 other lowers with me, tried them both, tried his with my buffer and spring. My buffer is a Spikes T2, same problem., tried my lower with his carbine buffer and spring. same problem
We ran a full 30 round Pmag through it.. rechambering sparatically all the way through it thinking maybe it just needed some break in... same problem. We decided then that it was definetly not a lower problem but a problem with the upper.
He called wester sports online, very friendly people but they told him that AA pinned these at the factory and he needed to call them. They gave him AA's # and the Head rep's name for thier service.
He has Called AA now, they told him he needed to use a carbine buffer, which he is, he did try my T2 but only as an attempt to diagnoise the problem. They also said that BAD levers have caused this same problem. strange though how we tried 2 different lowers with no BAD lever on them and it did the exact same thing. But he has now taken off his BAD lever, and will try and shoot tmrow. I will keep you all posted as to how AA is going to handle this CS wise.