Building an AR

[MagRelease]

Hey guys,

If anyone could give me a brief list of what parts you would need to build an AR, I would appreciate it... Also if you don't mind, just assume that I have no idea what any abbreviated terms stand for, because in the realm of AR parts I most likely actually will have no idea.

In case there is a ban, I would like to do whatever I can to buy or build one... Which I am well aware of the difficulty in doing either right now due to the insanity with the market right now, but if I see some golden opportunities I want to make sure I at least know what I need to get to seize them.

My thinking is that I most likely will not have the money to get ahold of an already built AR (which has been the case for the past year), but it's possible I might be able to get atleast the important pieces of one before a ban passes.

Thanks.. Any help is greatly appreciated. Like I said I am aware of the circumstances, and know that it is most likely too late, but want to jump on any luck opportunities that might cross my path.

[animalmother85]

Lower receiver

lower parts kit
grip(sometimes included in parts kit)
buffer tube
buffer
buffer spring
castle nut for buffer tube
backing plate for buffer tube
stock

Upper receiver

forward assist with spring and roll pin
dust cover with clips, spring and pin(usually comes together)
charging handle
bolt carrier(bolt carrier group would be an easy bet)
barrel
barrel nut(will be dependent on fore end as to what type)
gas tube
gas block
Fore end of some sort, weather it be a free floating one or the regular. Magpul MOE are pretty nice yet cheap.
muzzle device

I think that's all. I may be missing something...that's just from piecing one together in my head.

[MagRelease]

Lower receiver

lower parts kit
grip(sometimes included in parts kit)
buffer tube
buffer
buffer spring
castle nut for buffer tube
backing plate for buffer tube
stock

Upper receiver

forward assist with spring and roll pin
dust cover with clips, spring and pin(usually comes together)
charging handle
bolt carrier(bolt carrier group would be an easy bet)
barrel
barrel nut(will be dependent on fore end as to what type)
gas tube
gas block
Fore end of some sort, weather it be a free floating one or the regular. Magpul MOE are pretty nice yet cheap.
muzzle device

I think that's all. I may be missing something...that's just from piecing one together in my head.

Awesome, thank you!

[SCBaldr]

I would suggest ordering parts in kits to minimize the chance of forgetting something.

When buying rifles, keep in mind that the barrel is the beating heart of any rifle. Its good to shop/build for the features that you want, but the quality and configuration of the barrel is what matters most in my experience. So here are some of the things you will see and brief explanations. I don't mean to treat you like a novice. (You're probably going to shoot more rifle ammo than I do in a year) but someone else who has the same questions may come along and read a bit and get a better idea of what to order / look for. So here goes the barrel info.

5.56mm x 45mm NATO v. .223 Remington, go by the barrel stamp, not the receiver stamp. If it says 5.56 NATO on the barrel, you can use both 5.56 NATO and .223 Remington. If it says .223 Remington on the barrel, use nothing but .223 Remington as the NATO round has a very slightly steeper shoulder and runs at a slightly higher pressure.

Quality barrels are usually made of a 4000 series medium carbon chrome-moly steel such as 4140 or 4150, though some stainless barrels are made of 6000 series high chrome/vanadium steel and have been shown to be quite good.

Stainless Steel (SS) Just means that the barrel is made of an alloy that has enough chromium and nickel in it to be dubbed stainless. These barrels are best used for getting ultimate pinpoint accuracy. They can be more sensitive to ammunition differences and filth than CL barrels. If you are building a dedicated target AR, this is the choice for you.

Heavy profile barrels will retain their tight grouping characteristics as the barrel heats up. Med-con or Government profile barrels offer a good balance of relatively tight grouping when hot and lighter weight. Lightweight or pencil barrels are very light but the individual rounds will wander a bit once you get it hot, which wont take that many shots.

For ammo that is 62 grain and heavier, go for 1 in 7" twist rate, for ammo that is lighter than that, 1 in 8" and 1 in 9" are fine.

Cold Hammer Forging (CHF) is a process in which the power hammer that forges the barrel around the mandrel is internally cooled (in some cases, the mandrel itself is internally cooled) to bring the forging temperature down and create a tougher, denser barrel material.

Chrome Lining (CL) is a plating of Chromium on the inside of the chamber and barrel. A thin plating is about .003" thick while a very thick plating like those found on CL barrels made by FN Herstal is somewhere between .011" and .013" thick. (Thickness of plating has nothing to do with accuracy, but everything to do with barrel life) This reduces friction, extends barrel life and makes chambering and extraction easier at the expense of pinpoint accuracy. (My rifle has a CL barrel and will routinely shoot sub-MOA at 200 yards or better with 69 grain match ammo.) Its all in how you break the rifle in. So take that for what its worth.

Magnetic Particle Inspected (MPI) is a non-destructive inspection of the barrel steel which uses electro magnetism to look for microscopic flaws in the finished barrel.

High Pressure Tested (HPT) parts are those that have been tested at maximum proof levels with absolutely zero dimensional change after testing. Its really a comfort factor thing and has little to do with normal function.

Well, there is the general AR barrel info. I hope that adds something constructive to the board!

[solrac7]

Not sure if you realize or not, but you will also need a lower receiver in addition to the parts kit. The lower receiver is also the part with the serial number - and requires the FFL paperwork. They are very scarce right now, and all parts have at least momentarily skyrocketed in price.

Good luck, Cb

[MagRelease]

I would suggest ordering parts in kits to minimize the chance of forgetting something.

When buying rifles, keep in mind that the barrel is the beating heart of any rifle. Its good to shop/build for the features that you want, but the quality and configuration of the barrel is what matters most in my experience. So here are some of the things you will see and brief explanations. I don't mean to treat you like a novice. (You're probably going to shoot more rifle ammo than I do in a year) but someone else who has the same questions may come along and read a bit and get a better idea of what to order / look for. So here goes the barrel info.

5.56mm x 45mm NATO v. .223 Remington, go by the barrel stamp, not the receiver stamp. If it says 5.56 NATO on the barrel, you can use both 5.56 NATO and .223 Remington. If it says .223 Remington on the barrel, use nothing but .223 Remington as the NATO round has a very slightly steeper shoulder and runs at a slightly higher pressure.

Quality barrels are usually made of a 4000 series medium carbon chrome-moly steel such as 4140 or 4150, though some stainless barrels are made of 6000 series high chrome/vanadium steel and have been shown to be quite good.

Stainless Steel (SS) Just means that the barrel is made of an alloy that has enough chromium and nickel in it to be dubbed stainless. These barrels are best used for getting ultimate pinpoint accuracy. They can be more sensitive to ammunition differences and filth than CL barrels. If you are building a dedicated target AR, this is the choice for you.

Heavy profile barrels will retain their tight grouping characteristics as the barrel heats up. Med-con or Government profile barrels offer a good balance of relatively tight grouping when hot and lighter weight. Lightweight or pencil barrels are very light but the individual rounds will wander a bit once you get it hot, which wont take that many shots.

For ammo that is 62 grain and heavier, go for 1 in 7" twist rate, for ammo that is lighter than that, 1 in 8" and 1 in 9" are fine.

Cold Hammer Forging (CHF) is a process in which the power hammer that forges the barrel around the mandrel is internally cooled (in some cases, the mandrel itself is internally cooled) to bring the forging temperature down and create a tougher, denser barrel material.

Chrome Lining (CL) is a plating of Chromium on the inside of the chamber and barrel. A thin plating is about .003" thick while a very thick plating like those found on CL barrels made by FN Herstal is somewhere between .011" and .013" thick. (Thickness of plating has nothing to do with accuracy, but everything to do with barrel life) This reduces friction, extends barrel life and makes chambering and extraction easier at the expense of pinpoint accuracy. (My rifle has a CL barrel and will routinely shoot sub-MOA at 200 yards or better with 69 grain match ammo.) Its all in how you break the rifle in. So take that for what its worth.

Magnetic Particle Inspected (MPI) is a non-destructive inspection of the barrel steel which uses electro magnetism to look for microscopic flaws in the finished barrel.

High Pressure Tested (HPT) parts are those that have been tested at maximum proof levels with absolutely zero dimensional change after testing. Its really a comfort factor thing and has little to do with normal function.

Well, there is the general AR barrel info. I hope that adds something constructive to the board!

Actually I am quite pleased at you posting as if I were a novice, because I am in most regards.. I know some of what you have posted, but the rest was certainly very informational. Thanks!

[MagRelease]

Not sure if you realize or not, but you will also need a lower receiver in addition to the parts kit. The lower receiver is also the part with the serial number - and requires the FFL paperwork. They are very scarce right now, and all parts have at least momentarily skyrocketed in price.

Good luck, Cb

I am aware that the Lower needs to be transferred via FFL, would I be correct in assuming that the lower is probably the most important part to buy first? Hypothetically speaking, could I buy ONLY the lower right now and build the rest after a ban (if it were the same as the last ban of course)?

[Gun]

Hypothetically speaking, could I buy ONLY the lower right now and build the rest after a ban (if it were the same as the last ban of course)?

Good luck with that, unless you have deep pockets. By the time lowers MIGHT be available, you can source some books from Brownells on the subject of AR assembly, and become an academic on the subject.


Go to M4Carbine.net, read the stickies for internet info, if books aren't your thing.

[MagRelease]

Good luck with that, unless you have deep pockets. By the time lowers MIGHT be available, you can source some books from Brownells on the subject of AR assembly, and become an academic on the subject.


Go to M4Carbine.net, read the stickies for internet info, if books aren't your thing.

Like I said, I am aware of the circumstances, just informing myself incase a lucky opportunity falls into my lap.

[solrac7]

Yup,
The lower is what you need first - IF you can find a metal one for under $200 (now... used to be $50-$99) BUY IT. You are unfortunately late to the party, and all of the pretty girls and good food is gone. I wouldn't pay more than that, if you cant find one, I would wait and keep looking - IF a ban doesn't go through right now (big if) you may be able to find people selling their panic buys for needed cash before the next big ban push which WILL come...
The part I had the most trouble getting before this panic was the Bolt Carrier Group (BCG) that is the part that holds the firing pin and slides back and forth - and makes the rifle go BANG! ;-)

Cb