I've owned several and worked on them - swapped parts and components, but I've never built one from scratch.

I decided it's time some of the stripped lowers I've got in a box need to get used. I know what configuration I want, I know who to get parts from, and how I want to accessorize it. What I'm asking for things y'all learned the hard way, so I can possibly avoid doing something dumb.

Purchase good quality tools.   Proper tools, that are not the cheapest you can find, help prevent damage and breakage.  Cheap tools (and cheap Rifles) are cheap for a reason.

Obsidian Arms AR-15 complete armorer's 12 piece punch set
AR upper receiver vise block
Real Avid Master AR bench block
MagPul Armorer's wrench
Midwest Industries upper receiver rod

Seconded on tools. Buy roll pin punches. You can make do without them,  but...buy roll pin punches.

Triple check spring placement in your trigger group.

https://www.ar15.com/forums/AR-15/Build-It-Yourself/4/


https://www.ar15.com/forums/ar-15/Assemble_your_own_LOWER__UPPER__FREE_FLOAT__TRIGGER__GAS_BLOCK___Step_by_step_instructions_/4-226782/

https://www.ar15.com/forums/ar-15/-/4-615304/&page=1

With the parts that like to fly, I used a big ass ziploc bag with lower inside. No I know better.

Obsidian Arms roll pin starter and finish punches are superior to Wheeler tools.  4140 alloy steel, heat-treated and QPQ-Nitride finished.  The set comes with a lifetime warranty. If you break a punch, the company will replace it at no charge to you.

They are professional grade tools, made in the USA.

https://www.plastixrevolution.net/collections/ar15-upper-vise-blocks/products/223-ar-15-308-ar-10-upper-receiver-vise-block

Have an oops kit on hand.

I agree with the tools suggestion, but I like the Real Avid AR15 kit more than anything else, though they’re mighty proud of it.

Get a 5/16 chucking reamer to ensure that the holes on the gas block and gas tube are drilled correctly, never had trouble since I started doing this.

I’m also a fan of dimpling the barrel if it’s not done from the factory.  Guarantees perfect gas block alignment.  Can just do the one dimple.  Use a little Hot-Lock on the set screws & it ain’t ever going anywhere.

Geissele gas block install kit/block can be very helpful, especially when coupled with a quick-grip vise.

On top of that, make sure you use aeroshell on the buffer tube, not just the barrel nut.

Finally, an automatic punch can help with staking the castle nut, if you don’t like doing it with a hammer, even if you just get the initial dent with the automatic punch.

I have some good tools, since I work on a lot of other things. Punches and such are covered and I have a big bench vise. I have 2 'AR assembly' multi-tools I've acquired over the years, but I don't know who made them now. I got one for swapping buffer tubes or something.


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Thank you.

I knew threads like this existed, but I hadn't found them yet. Once I get the tools I'm missing and the parts I haven't got yet, I'm going to get on it.

I have one upper that needs a lower I can put together to start, and then I'm on to building up an entire, functional (hopefully )rifle from a stripped lower.

Oh - that does look useful. I was going to get a clamshell thing I saw, but this looks like a much better option. Thanks This is exactly the sort of thing I was hoping for!

I've pieced together/tore down many guns with a clamshell block, don't underestimate their usefulness.

I have that set. It has successfully assembled more than a dozen rifles thus far. I think the only AR tool that I don't have is an action rod. I've never had any issues installing or removing a barrel.

OP: Go slow, don't force anything, and think about the order you do things in. A little lube in the proper areas can help as well.

The real avid kit I mentioned has a rod like that included.  MI has the extra feature of the top support, never been an issue though.

Great advice here, but the most important thing is to have fun doing it!

It shouldn’t be a stressful exercise, just remember that if you might change your mind about something later, you can always alter the build…that’s the beauty of the platform!