What is a mac 11 upper? Find Out Everything You Need to Know!

Alright, folks, gather ’round, let me tell you about this little project I’ve been tinkering with – building a mac 11 upper. Sounds a bit wild, right? But trust me, it’s been a ride!

So, first things first, I got my hands on a parts kit. Now, these kits can be found in various conditions. I was lucky to get one in pretty good shape, but I still needed to make some decisions on what to keep and what to replace.

Next, I started inspecting all the parts. The barrel was in decent condition, so I decided to keep it. The trunnion, though, looked a bit rough. I weighed my options and figured it would be best to get a new one. It’s a critical part, so no point in skimping there.

With all the parts sorted, I moved on to the receiver. I opted for a flat receiver blank. Bending it was the next big hurdle. I dusted off my trusty bending jig, and after a few careful measurements and a lot of double-checking, I bent the flat into shape. It wasn’t perfect, but hey, it was my first time, and it was functional.

Welding was the next step. Now, I’m no expert welder, but I know my way around a welder. I took my time, made sure everything was aligned, and tack-welded the trunnion and other bits to the receiver. Then came the full welds. Slowly but surely, I joined everything together. It was a bit nerve-wracking, not gonna lie, but I managed to get it done without any major mishaps.

After the welding, it was time for some cleanup. I ground down the welds, smoothed out the rough edges, and gave the whole thing a good once-over. Then came the heat treating. This part was a bit tricky, but I followed the instructions to a T and hoped for the best. Thankfully, it all worked out, and the receiver was now hardened and ready for action.

Next up, I installed the barrel. This involved pressing it into the trunnion. I used a hydraulic press for this. It was a bit of a tense moment, making sure everything was lined up perfectly, but I got it in there nice and tight.

With the barrel in place, I assembled the rest of the upper. I added the bolt, recoil spring, and all the other small parts. It was like putting together a puzzle, but way cooler. And honestly, seeing it all come together was a pretty awesome feeling.

Finally, I test-fired it. Safety first, of course! I loaded up a few rounds and headed to the range. The first shot was a success! It fired perfectly. I fired off a few more rounds, and everything functioned flawlessly. It’s not going to win any beauty contests, but it works, and that’s what matters.

What I Learned

• Patience is key: Rushing things will only lead to mistakes.
• Measure twice, cut once: This applies to everything, from bending the receiver to welding.
• Safety first: Always wear proper safety gear and follow safe practices.
• It’s okay to ask for help: There are plenty of resources available, so don’t be afraid to use them.

Building a mac 11 upper was a challenging but rewarding experience. It’s not something I’d recommend for everyone, but if you’re up for a challenge and have the right tools and knowledge, it’s definitely doable. And hey, if I can do it, you probably can too!