Alright so I finally got my hands on this MTZ 556 kit I’d been eyeing for ages. Saw folks online struggle with it, figured I’d document my own build, warts and all. Maybe save someone else the headache. Here’s how it went down.
The Unboxing Mess
Cracked open the box expecting organized parts. Yeah, right. Springs, pins, tiny ass washers – everything dumped together like a junk drawer. Took me a solid thirty minutes just to spread it out on my workbench and match parts to the blurry printed diagram. Good start.
Lower Receiver Drama
Started with the lower receiver. Seemed straightforward enough. Slapped in the trigger assembly. Mistake number one. Hammer spring looked twisted in the diagram, thought it was backwards. Tried forcing it. Oh my god, that little spring flew across the room. Spent ten minutes crawling on the floor. Found it under the fridge. Lesson learned: look closer at the damn spring orientation before muscling it in.
- Hammer pin went in okay, stubborn but manageable.
- Trigger pin? Absolute cheap garbage. Metal felt soft. Almost rounded the edges trying to tap it through. Gotta go slow, lots of lube. Cheap tools = bad time.
Bolt Carrier Group Fun
Thought the BCG would be easy. Heh. Getting that firing pin retaining pin lined up? Pure frustration. Tiny hole, stiff pin. My fingers are not built for this. Ended up using needle-nose pliers and a whole lot of swearing. Had to tap it the last little bit with a punch. Felt like I wrestled it in.
Gas System Headaches
Alright, the gas block. This is where it gets worse. Slid the tube into the block. Seemed fine. Trying to line it all up with the barrel and get that pin through? Nightmare. Roll pin kept squishing sideways instead of going in. Wasted time trying to tap gently. Ended up using a vice block to hold everything super steady and whacked it harder with my punch. Finally seated. Sweat was involved.
Stupid Little Washers
Handguard time. Looked slick. Only issue? Those stupid little anti-rotation washers. Needed four. Found six in the bag. Which ones? Where? Diagram offered zero help. Guessed. Tightened the screws hoping I got it right. Seems solid? Fingers crossed.
Final Assembly & The Moment of Truth
Slapped upper and lower together. Pin slid in smooth for once. Minor win. Attached the cheap plastic stock it came with. Not fancy, but it’ll do. Charging handle felt gritty at first. Worked it back and forth, added a drop of oil. Smoothed out okay. Loaded a dummy round just to check feeding. Pulled the trigger. Click. Hammer dropped. Looked like it fed fine. Seemed to work.
First Shots Later
Took it out back later after checking everything thrice. First few rounds cycled a bit rough. Probably still needed breaking in. After a mag, things started smoothing out. Ran okay. No explosions, no gas in my face. Call it a win. Not the smoothest build, but I got it done without breaking anything major. Mostly. That damn firing pin pin though…
