Meh... i expected more for this kind of money
This receiver set, although apparently CNC made, is not for everyone - if you want to install it you better have additional tools (dremel, drill, proper workbench) or you will not be able to make necessary modifications during installation, for example:- even when upper assembled with lower without any gearbox inside, i couldn't push the front pin between holes to close the receiver - i had to use 6mm HSS Titan drill bit, and battery operated drill with tunable RPM in order to make additional widening of the hole without taking too much material so the front pin would slide easily- magazine release catch hole is not wide enough - again i had to use same 6mm drill bit and widen the hole so i can insert any kind of magazine release catch- receiver comes without dummy bolt catch - the ones you can buy like SHS or similar (with pin) will not fit, so now i have a rifle without bolt catch, luckily i do net worry about aesthetics, but...- the magwell on this receiver is wery finnicky, it is very tight, so in case you have CYMA Magpull type they will not fit inside, Ares Amoeba short hicaps (120 round) will also not fit (magazine release catch will not catch the magazine, they keep falling out). The only magazines that i have and that work with magwell are G&G polymer midcap (80 0r 90 rounds), Modify XTC midcap (190 rounds), Hakkotsku M4/UAR short hicap (140 rounds), G&G hicap (330 rounds)Anyhow for the price of 190 EUR (ok i got 15% discount) i expected less problems and more out of the box installation, however i just got a lot of disappointment, this was my first and probably my last Madbull brand product that i will ever buy... :-(