Building up an AR15 isn’t as difficult as you might first think, there are certain processes that can be put into place that can help you build and even customize your AR15 rifle. All it takes is patience and a little bit of prior knowledge which we are about to give you here. All you need to remember is that we are building a rifle here and incorrect assembly could be dangerous so please follow these steps carefully.

Assemble an AR 15 Rifle

Deciding on What Rifle to Assemble

Firstly you will have a choice of different upper receivers to select from, the A1, A2, A3 and Flattop which all have different features and are used for different reasons.

The A1 in particular has a fixed carry handle, like the A2. There is also shell deflector with the A1 that needs to have an ejector port cover assembly, forward assist assembly, and A1 sight assembly installed. The A2 is very similar but is best used to shooting matches rather than the A1 which is more directed at retro civilian versions of the M-16 rifle.

The A3 looks totally different and sports a flattop with picatinny rail, a shell deflector and needs the installation of the forward assist assembly, as well as the ejection port cover assembly. This is the military upper of current times and is used to build a civilian copy of the M4.

Finally the last upper receiver is the one that you can really get to work on in terms of configurations. The AR-15 Flattop upper receiver can be built and used for pretty much anything you need it for, basically because you can fit any optic to the top of the rifle.

Assembling the AR-15

Make sure that you have a wide-open area to work in and lay out all the AR-15 parts in clear view so you can begin to see which parts go where.

The first area we are going to cover off is the forward assist assembly mount on the upper receiver. You will need to turn the receiver upside-down so that the rail is lying next to your work surface. Once you have put that in position then you can push the forward assist spring onto the forward assist.

Next, take the forward assist pin and slide it into the bottom of the upper receiver. If done correctly, it should stand all by itself.

Now press the forward assist assembly onto the upper receiver. While you compress the assembly, drive the pin through until it is flush with the receiver. When the pin is firmly started, you don’t have to hold the forward assist in place and you can drive the pin into the it using a large brass punch until it is not sticking up.

The final step in this process is to just test that the forward assist moves freely. If it’s a yes, then the process is complete.

Fixing Together the Bolt Carrier

First things first, you will need to find the bolt carrier and then press the bolt the whole way into the end of the carrier. You should make sure that the hole in the center of the bolt is aligned correctly. If this section has been completed successfully then you will now need to insert the bolt cam pin into the hole that is in the carrier itself. This can be difficult to do so you may have to work a little to get the bolt to go through the hole.

Once you have completed that step get the firing pin and just push it through the bolt carrier until it comes to a dead end (in the direction towards the bolt).

At the end of the process the bolt should be able to move freely, both in and out of the bolt carrier.

Finally Assemble the Charging Handle

The final difficult part of an AR-15 assembly is the charging handle. This process will make sure that the assembly of that upper receiver is complete, and that you are happy with the fit and movement.

Take the upper receiver and then turn it over so that the rail is flat against the surface of your work top once again. As soon as you have done this you will now need to insert the charging handle assembly by looking at the grooves on the upper receiver and then matching them up so the fit is correct.

When you come to fitting the bolt carrier you must make sure that the bolt is fully pulled out before you push it into the upper receiver as it just won’t fit if the bolt isn’t pulled out. If you are happy so far then just make sure that when you come to insert the bolt carrier assembly that you do so with the bolt facing towards the barrel threads).

To know that the assembly has fitted together you should here a click from the bolt carrier assembly and the charging handle assembly as they fit firmly into place in the upper receiver.


There are other factors that you can take into account when putting together an AR-15 rifle but these are custom components that not everyone will need. Also, it’s worth pointing out that an AR-15 assembly will vary dependent upon the upper receiver that you have chosen from earlier on in this article.

Before using the rifle make sure that everything is assembled correctly by carrying out a few final checks on every aspect of the rifle. Remember that an incorrectly assembled gun can lead to problems down the line so it’s always worth taking the time and patience to do this process once and to do it right.

If you are also lacking any AR-15 parts then you can go to your local gun hardware store where you should be able to pick up any missing parts. Or as an alternative you could buy them online and get them delivered to your house. Do not under any circumstances try putting one of these guns together with missing parts.

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