Did not cycle. visable fouling (gas leak) deposited on barrel, under the gas tube where it connects - Aero Precision M4E1 18in .223 Wylde Complete Upper Receiver with Flash Hider

Did not cycle. Visible fouling (gas leak) deposited on barrel, under the gas tube where it connects to the barrel. I shot about 30 rounds and had around 50% failure to feed. I tried this upper on 2 different aero lowers and 2 aero BCGs before inspecting the gas block and seeing the described deposits. (I did give a quick inspection and light cleaning prior to going to the range.)

Very disappointed on the performance. But I'm even more disappointed to read similar reviews of Aero precision customer service giving some shadey responses; They have a problem and I would expect a company to stand by their product.

They have / had a good reputation, hope this is not trend. But just to be safe, I will be looking elsewhere for my next upper.

Note, I have 2 other aero rifles that work great.