First AR Build - What Should I Know?

[rg115]

Been thinking about putting together my first AR-15 for a minute now. Finally started digging into parts and man, there are some pretty good deals if you know where to shop. But honestly, I'm kinda lost on what's worth it and what's not.

I'm aiming for a basic rifle build. Sticking with 5.56 for now since that seems pretty standard, but I'm totally open to other calibers if you've got good reasons to suggest them for a newbie.

What brands should I steer clear of? I've read some mixed reviews about certain parts. And what about those sneaky costs that pop up? I've heard people mention things like specialized tools or extras you don't think about at first.

Is it better to just buy a completed rifle? Or is building one something I should try? Any of you have stories about your own first builds? Would love to hear any tips or hard lessons learned. Thanks!

 

[the_leper_colony]

FWIW, I'll post a few thoughts and you can see what you think.

Caliber might depend on your intended use. If it will be a hunting rifle, pick an appropriate cartridge. Ditto for competition, self-defense, or general range use/plinking. Keep the cost of ammo in mind - I think .223/5.56 and 9mm are currently the cheapest centerfire options, while some of the big bore cartridges cost an arm and a leg.

Buying vs building might depend on a few different considerations. The tools needed to assemble an AR do cost money, and if you're thinking one AR will be enough for you, then buying a factory AR might be the cheapest (and most reliable) option. Nothing wrong with that, at all, and keep in mind that it's often possible to use different upper assemblies on the same lower (so one lower might be enough)!

And there are different approaches to building: buying a parts kit that includes a factory-assembled upper means you only need the tools required to assemble the lower receiver (that's how I did my first one). The tools needed to properly install the barrel in a stripped upper receiver are some of the more expensive tools required, and you can skip that expense if your kit includes an assembled upper. Plus, if you buy a complete parts kit (rather than buying parts one at a time from multiple sources), you will probably avoid compatibility issues, like buying a gas block that won't fit inside your forend, or buying a stock that doesn't fit your buffer tube/receiver extension.

Whether you're buying or building your first AR, I might recommend keeping the KISS Principle in mind - something close to an original military configuration (M4, M16A4, etc.) might be cheaper AND more reliable than a 'tricked out' AR with a bunch of exotic aftermarket parts.

One final thought - IMHO, if you decide to buy a complete rifle, I would recommend factory new (or maybe police surplus), from a reputable FFL. There are a lot of used 'parts guns' out there, and not all of them were assembled by experienced builders, using decent parts. I got interested in 'building' rifles years ago, when surplus military FAL parts kits cost $129 (including chrome-lined barrel ;^) and an FN-licensed forged steel FAL receiver was about the same price! When the FAL kits dried up, I swapped to 'building' AKs, when AK parts were in the same price range. Based on those experiences, I wouldn't touch a home-built AK with a 10 foot pole, unless I personally knew the builder! And while ARs are a lot simpler to build, some folks still have issues getting them assembled and running right, and you don't want to buy somebody else's problems.

As always IMHO, FWIW, YMMV, etc...

 

[VenomBallistics]

when assembling the lower with standard mil spec ... safety first, then the trigger, then the hammer. You want the hammer spring riding on top of the trigger pin. the trigger pin will walk if you don't do this.

There are too many brands churning out parts for the platform to definitively say what to avoid.
However ... Palmetto State Armory has been something of a hero of the build. with reasonably priced lowers.
get your lowers first, as these require an FFL transfer. the rest is built at your leisure.
When I got into this, PSA was selling them in packs of 3.
I recommend more than one out of the gate. Most of the real show is in the upper assembly.
In my case, the first two took direction while the third languished in a drawer as a bit of a bench mistress.
The first was a classic mid length gas system build.
PSA was running a special on upper assemblies at the time so I grabbed one in the interest of getting one done.
This runs perfectly, and more or less remains exactly as it was first assembled.
if we look at the M4, it sports a 14" thunder pipe and a shorter "Carbine length" gas system. your build should be 16" or greater for legal reasons. The theory was that the mid length system helped regulate the timing with the longer barrel. It might hold some water. My ejection pattern is absolutely perfect and function is very reliable.
You're not wrong to go for something of a "boring" by the numbers build. There's plenty to learn in there if you know to look for it.
My next build was in 9mm. You'd be a fool to ignore this option though it has a few challenges.
These are blow back. it does not lock up into battery like it does with it's native gas system. We compensate for this with buffer weight. Odin Gunworks has an adjustable 9mm buffer that will address this issue. When using Odin adjustable buffers, get to be good friends with locktite. Once you have your tune, blue juice it.
The end result is a fun small game appropriate carbine that'll have your ruger 10/22 gathering dust.
If you cast and reload, the Lee 6 cavity 120 grain TC mold is a reasonable investment, as is a toaster oven and a harbor freight powder coating gun.
The main thing with the 9mm build is the magazine. There are two ways you can go ... Colt SMG or Glock.
Having built for both, I have to say I prefer the Glock pattern. It offers more options. From the 10 round glock 26 mag for a lean and mean little bunny buster, on up to a 3D printed 60 round drum that makes you say "Now that's Italian", it has something to offend everyone.

Extra credit, there are a number of worthwhile cartridges that'll run in the AR. Often times you need only build an upper for that cartridge and simply swap upper assemblies much like a barrel swap on a TC Contender