Read before purchasing - Aero Precision M4E1 Threaded 10in .300 Blackout Complete Upper Receiver with Flash Hider

That’s what you should do… read the description of what it is that your buying… please don’t even pay attention to the bad reviews because I’m 100% sure those are just people who seem to find something wrong in anything and everything. They could win a million dollars and would say “ it said I won a million, it didn’t say that there would be taxes, terrible description, I wouldn’t recommend anyone plays the lottery ever again”. This upper is A++ beautiful, the craftsmanship is on point, at least 1000 rounds through with no problems, all I had to do was buy a charging handle and bcg just like it says to in the description LOL. Seriously tho, I would recommend to anyone. I’m very happy with my purchase and look forward to buying more of their products.