TLDR Version: What are some good reliable complete uppers with the magazine in the ~$700 range?
I ordered a complete 450 bushmaster upper (bushmaster brand with 16" barrel) from Midway USA in late June and finally got a chance to shoot a couple of weeks ago. I had issues from the first round. Stovepipe, failures to eject, failures to feed, double feeds...it was a frustrating range day. I was able to determine that the issues were between the extractor and the magazine. I tried it on two separate lowers, but got the same result. I have a few AR's but I'm no expert, so I decided it was better to exchange it for a new upper; hoping I just got a bad one (the reviews on the upper are excellent). I got the new upper yesterday, and it is doing the EXACT same thing as the previous one. I tried this upper on three separate lowers, to no avail. The gun failed to operate with any of them - and failed in the same ways with all of them. Apparently the QC at Bushmaster has taken a hit lately. I'd be very surprised if either upper was tested before leaving the manufacturing area - there is no way either upper would've fed and shot two rounds sequentially. I returned the second upper for a refund. I'm not messing with another Bushmaster brand upper - time to move on.
I'm now searching for a different upper and have looked through the forums here a lot. I'd prefer not to build my own upper since I don't really want to buy all of the tools necessary to do that. I'm looking to buy a complete upper with a magazine in the $700 range that I can slap on my lower and go.
Let me know what recommendations you have. I'm leaning toward Wyndham Weaponry and have looked at Tromix (a little pricey for me), but am curious what other recommendations are out there. TIA