Building a 80% AR

[MMH]

What is the typical cost for a complete build on a 80% AR? I figure $150 to $200 for the lower & jig kit, but what do all of the other parts run? Looking for a good solid build, nothing exotic. Would be a free float quad rail.

Please confirm or correct my understanding: On a 80% gun, no NICS is required but I cannot sell the gun. Can I build an AR pistol or just a rifle?

[imashooter2]

Just the first place I looked, Palmetto State Armory, $400.
https://palmettostatearmory.com/memo...ifle-kit9.html

[Walleye Hunter]

Durkin Tactical has kits too and you can find them at the larger gun shows. No NICS required, can build a pistol and if you build a pistol first, you can put a long barrel on it but not visa versa. I believe you can sell the gun with some requirements to be met but I am not sure on what requirements. Others here will know for sure.

[ExFlyinguy]

What is the typical cost for a complete build on a 80% AR? I figure $150 to $200 for the lower & jig kit, but what do all of the other parts run? Looking for a good solid build, nothing exotic. Would be a free float quad rail.

Please confirm or correct my understanding: On a 80% gun, no NICS is required but I cannot sell the gun. Can I build an AR pistol or just a rifle?

I haven't shopped the stuff for a while so I can't say how much a lower + jig might cost. I also had to buy a router + the bits (drill bits & end mill). It's not cheap

It's a false myth that you CAN'T sell a PMF(Personally manufactured firearm). You can't built it with the intention of selling it. Hypothetically if you owned it for a year and one day woke up with a desire to sell it you could do so. You can sell it in rifle configuration just like any other long gun.

You can build it as a pistol. If you later choose to sell it as a pistol though you will have to abide by PA handgun sales laws. *Off to transfer at a FFL & it will have to be serialized by the FFL. (as I now understand the latest ATF rules/regs)

[DavidH]

You can build one as cheaply or expensive as you wish. I*ve followed the 80% market from its widespread inception, about 2012. But I started using them only about 5-6 years ago. That*s because it took the market that long to really make them as good as they are now. In 2015, the 80%s were around, however, Jig kits were incredible expensive! And the Lowers themselves were either standard Forged MilSpec in 7075, or in 6061 Billet only. And I would never use 6061. That is exactly what happened to the company I have used these last years. I was supplied by AMT Lowers. However, they started using 6061, and now they have stopped altogether because they are afraid of the ATF. So I recently switched to a new supplier.

Here is the Billet AMT 80% Lower I have used, and machined many of these. Granted, I did like them when they were 7075.


Here is the new 80% Lower I*m using from now on. These are nicer. They actually have the *enhanced* features. The 4-40 set screw for the rear detent & spring, the 308 pin for the Bolt Release, & threaded hole for nylon tip screw to take out the *rattle*. Just as the Aero M4E Lower has. These also have much nicer flared Mag Wells., & are more visually appealing overall, I think. They do cost a bit more than I was paying for the AMT Lowors, but isn*t everything more expensive? LOL!



Here is my last build using an AMT Lower when they were still 7075 Billet. Running a Ballistic Advantage 16* Premium Black Barrel, and my list of *Go to* premium parts. I*ve used SureFire Flash Hiders since like 2018. Several builds using them. The 3P Eliminator. However, I had this Surefire Warcomp Flash Hider my son wasn*t using, so I*m trying it out instead. Pictured is a 7075 FF handguard, which I do like, but on the next I*m switching to a 6061 Handguard rail because it*s clamp on & has a better barrel nut. Doesn*t really matter the material with handguards as they aren*t load bearing. The Barrel Nut is what*s important. Don*t ever use those cheap barrel nuts! Make certain it*s either steel or 7075-T6 Aluminum. Just make certain the rail/handguard you purchase is US made & it will be fine. Which goes for everything! I use *Clamp On* Gas Blocks, both fixed & adjustable. Like adjustable because the rifle will fire ANY 223 in existence without a hitch. Or can turn the gas off to make it a straight pull Action. I*ve used different buttstocks. For years I only used the Ergo F93. But my liking has changed, so I*ve been using the Kriss for a couple years. But, pick your poison, so to speak. Same for all the furniture. I do like Titanium small parts. Pins, the Castle Nut, etc. Triggers.. yeah triggers are one of those things people go crazy about. I*ve been doing my own triggers for over 2 decades. Gained a ton of knowledge from building 1911*s because EVERY trigger must be fit. They don*t have *drop in* 1911 triggers. Well, I guess now they do. But I wouldn*t use them. But I digress. If I was going for a target AR, I*d use a 2-stage. But since I*m not, I like my AR triggers about how I like my carry gun. Around 5lbs with smooth, no grit take up. Glass brake and little-no overtravel. I*m just not willing to spends hundreds of dollars on an AR trigger that is 3lbs or less. I generally use ALG triggers, and surface prep them myself. They are good quality, MilSpec (but better), triggers. Again, go with what you want. Want a Timney or POF or Rise Drop-In? Or perhaps a a Giessele National Match? Go for it!


I*ll tell you I generally spend about $1200. But that has all the best parts one can use. I could easily build one of my 80*s for $700 or so. And it would compete with any of the manufacturers ARs. And it would still likely be more accurate.

[MMH]

You can build one as cheaply or expensive as you wish...

Nice post, thanks for all of the insights. I understand that 7075 is much stronger than 6061. Do lowers need that strength? I understand why the military needs it, but I won't be jumping out of planes and breaking down barricades with my rifle. Can you list/provide links some of the manufacturers that make quality lowers? You showed what you use now but I was not sure who was the manufacturer.

As far as kit, I would probably look for a completed upper from a quality manufacturer (I like Compass Lake Engineering). A good barrel (such as Bartlein or Kreiger) will be $400 to $600 alone. Accuracy depends mostly on the barrel and to some extent the upper so I would not mess around here - I like accurate guns! I would not spend a ton on the trigger - a tuned up mil spec trigger works great.

[MMH]

I haven't shopped the stuff for a while so I can't say how much a lower + jig might cost. I also had to buy a router + the bits (drill bits & end mill). It's not cheap

It's a false myth that you CAN'T sell a PMF(Personally manufactured firearm). You can't built it with the intention of selling it. Hypothetically if you owned it for a year and one day woke up with a desire to sell it you could do so. You can sell it in rifle configuration just like any other long gun.

You can build it as a pistol. If you later choose to sell it as a pistol though you will have to abide by PA handgun sales laws. *Off to transfer at a FFL & it will have to be serialized by the FFL. (as I now understand the latest ATF rules/regs)

Do you have to somehow identify that you built a pistol? What about the other AR15s in the safe. I have a lot of rifles. If I would build a pistol and have a couple of uppers for it, would the ATF interpret it as constructive intent? In other words, would they say that the other pistol upper was for one of my rifles?

[ExFlyinguy]

Do you have to somehow identify that you built a pistol? What about the other AR15s in the safe. I have a lot of rifles. If I would build a pistol and have a couple of uppers for it, would the ATF interpret it as constructive intent? In other words, would they say that the other pistol upper was for one of my rifles?

Having an 80% lower that you complete to a finished lower receiver is no different than if you bought a finished "insert brand here"(Anderson, Aero,) lower. It will be identified by having a pistol only buffer tube in it.

As far as the constructive intent of having more pistol length uppers than you have pistol lowers that's a personal call that you may wish to have input from a lawyer like Phil. Personally it's not an issue that would cause me discomfort, but I'm of the opinion that if ATF is looking through your safe you probably have bigger problems. Bottom line is if you have one pistol length upper and it pairs with a pistol length lower there is nothing stopping you other than your own law-abiding self from putting it on one of your rifle lowers.

IANAL

[DavidH]

Do you have to somehow identify that you built a pistol? What about the other AR15s in the safe. I have a lot of rifles. If I would build a pistol and have a couple of uppers for it, would the ATF interpret it as constructive intent? In other words, would they say that the other pistol upper was for one of my rifles?

Nothing to identify. When you buy a Lower, the PICS Check is done exactly like buying a pistol, vs buying a rifle. You don’t have to do anything else.

As for the material of the Lower, it doesn’t matter strength wise. The Lower is does not see the load factor that which makes strength a factor. The only issue is recoil “can” stretch the Take-Down/Pivot pin holes. However, never, NEVER buy a 6061 Upper. The Upper is a loaded bearing part & sees both torque & shearing factors. The point of wanting only 7075 Lowers is a personal point for me.

[cdi]

When the gun is fired, force is applied to the hammer and trigger pins through bolt carrier movement.
It pays to have a lower with hard coat anodizing to keep hammer and trigger pin holes round for a long period of time.
I*ve never seen takedown pin holes get egged out on a well made lower.
And as far as I*m aware all pics checks called into the Pa. State Police by an ffl are processed the same way wether pistol, rifle or receiver.