Officially Licensed Noveske N4 Gen. III Full Metal Receiver for Airsoft M4/M16 AEGs by Madbull (Color: Black)

"Solid receiver and happy with the end result. I had some similar issues as others have mentioned. The dustcover door is pretty crappy and mine pops open all the time, so it was replaced with one I had laying around. Due to the design of the Mag Release slot, it is hard to find a Mag Catch that fits directly, I had to bore our the hole on the lower receiver, normally the mag catch/release just need to pass through the gearbox shell. For the Bolt Release, I found that the Krytac Trident fits and the spring loaded design allows it the clear the upper when installing on the lower. https://www.evike.com/products/76658/

"Amazing product. Was very surprised with how good the quality Is. The other reviews said it didn’t come with a dummy bolt, but it did. The hop up is pretty good, but I am definitely going to replace it. My only problem is that it doesn’t work too well with the Magpul style hi-cap magazines, but that is more of the mags problem. Overall-
PROS:
Sturdy
Comes with all receiver accessories beside a bolt catch
High quality and good weight
CONS:
Had to drill a little bit to get the magazine catch to go in
Front pin is a little tough to fit when gearbox is in
Some polymer magazines don’t work

I will definitely be buying this again for another project!

"Excellent quality, very clear trades, sturdy finish. I have two problems with this receiver.

1) It's hard to put a MK18 rail onto it because the upper is so wide - it doesn't allow the screws to pass from the baseplate to the rail.

2) There is probably no bolt catch/release that fits this thing due to the same problem.

If you don't care about putting a RIS on, or having a bolt catch, buy this thing.

If you're curious about what it comes with, it comes with the retaining pins, dust cover (installed) forward assist (installed), charging handle (installed) and what I believe to be a milspec buffer tube set screw.

TL;DR - if you don't have a dremel, don't buy it.