Thanks for the input. I will have to research this topic more in-depth; I guess I only scratched the surface here.
I do see that there are threads on IC on how to DIY an AR; I'll look at those to see if I can convince myself that building my own is not that hard to do. I do have a question right off the bat: are there any specialty tools required to build my own AR?
The hardest part of building an AR is all on the upper. The 2 hardest parts are lining up the gas tube at the correct torque for the barrel nut and aligning the muzzle brake/flash hider using a crush washer (more important if using a brake, obviously).
By buying a pre-built upper it definitely takes away the difficulty.
Faxon makes an awesome line of barrel devices with "Muzzlock" that eliminate the PITA crush washer.
The barrel nut usually determines your handguard, especially if getting the better free float type. Different brands have different attachments to the barrel nut. Non free float handguards have to interface up against the gas block so it's just easier to do free float if building. Just make sure to use antisieze on your barrel nut if you ever want to get it off.
For the upper you need an armorer's block (or something in your vice to evenly distribute clamping without marring). Personally I'm a huge fan of the geissele reaction rod, and a similar device is required on less strong lightweight billet uppers. Instead of applying torque to the soft aluminum upper it applies torque to the stronger chrome lined steel barrel. But it's expensive compared to some wood blocks some people use.
I dont think armorers blocks are really needed for the lower, but it might make it a little easier. The buffer tube requires way less torque then a barrel nut. And you stake it (punch a piece of metal to expand into a notch) so it's not going anywhere. As long as you're not magilla the gorilla you could probably get by without a torque wrench for the lower as long as you stake the buffer tube. So for the lower you just need a buffer tube wrench. But armorers wrenches are pretty cheap outside the magpul one and that gives both the barrel nut, buffer tube, and muzzle device wrench, along with the squares to attach a torque wrench socket.
And the trigger really makes the gun, so there's another reason to at least build your own lower. Plus non GI triggers are easier to install. Spend some money here, it's worth it.
I've only built one AR and it was my first, there really isn't much to it, they're big kid Legos.
Edited by chicagoresident, 09 March 2018 - 09:28 AM.