Newbie AR15 Question

[DukkButt]

For building your own, highly recommend "The AR-15 Complete Assembly Guide" by Walt Kuleck with Clint McKee. Great step by step with lots of pictures, details and explanations. Note that this is volume 2. Volume 1 is more of an owners manual, I believe.

 

[MikeO1948]

AR-15s are popular because they are a blast to shoot, literally. They are easy to shoot; very little recoil. The ammunition is relatively inexpensive. Millions of Americans who have served in the military since the mid-sixties are very familiar with the weapon. They are great fun, and if ever necessary, a great weapon to defend the Constitution of the United States with. I own a Bushmaster AR, and the weapon came with a manual which anyone who knows one end of a rifle from the other can read and operate the rifle with no trouble. I assume most other manufacturers provide similar instructions. Nothing could be simpler than shooting an AR.

 

[qmcswret]

There are lots of videos on YouTube on how to assemble an AR from parts. Here's how it runs.

When you pull the trigger, the trigger and hammer, which meet at the sear, slip past each other. This releases the hammer.
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The hammer strikes the firing pin.
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The firing pin strikes the primer in the cartridge, and the fun begins. The powder in the cartridge expands to about 7000 times its original volume, which encourages the bullet to leave the vicinity post haste. The bullet travels down the barrel past a tiny hole a few inches from the end of the barrel. This is called the gas port. Once the bullet passes the gas port, the pressure behind it forces gas down a tube (called a gas tube) that goes back to the chamber.
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The tube sticks partway into the receiver and into the gas key on the top of the bolt carrier.
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The pressure from the gas pushes the bolt carrier back. The bolt, which is locked into the chamber in order to hold the pressure, can't come out until it turns a little bit.
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There is a cam in the bolt that rides in a slot in the bolt carrier. When the bolt moves backward, the slot and cam force the bolt to turn, which unlocks it.
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The carrier continues backward, carrying the bolt with it. On its way back, it runs into the hammer, and pushes it back into position so that you can pull the trigger again. The carrier is pressing against the buffer, which is in front of a big spring in the buffer tube.
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Somewhere about now (or maybe a little earlier), the bullet has cleared the end of the barrel, which reduces the pressure in the gas tube. That, and the buffer spring, cause the bolt carrier to slow and then stop. The buffer spring can now push the bolt carrier forward again, stripping another round from the magazine and pushing it into the chamber.
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The bolt turns a little once it's inside the chamber, which locks it in place again. And you're ready to fire again. As well you should.

Great explanation! I don't recall the last time I enjoyed learning something so much. Thanks!

 

[pietro beretta]

I don't recall the last time I enjoyed learning something so much. Thanks!

Next is reloading, that is; if you haven't already started yet

 

[Flopsweat]

Great explanation! I don't recall the last time I enjoyed learning something so much. Thanks!

Thanks! I had a lot of fun putting it together.

 

[Rich]

Think of the AR 15 platform as a car where you have a frame and engine and then have thousands of interchangeable parts that all can fit pretty much together on the frame. There are different doors, wheels, chairs, steering wheels, etc to choose from and for the most part they all fit up together. You can buy thousands of different pre-made ones or build your own unique one from scratch.

To start, you can go out and buy a basic AR15 complete rifle. Then have pretty much endless possibility of custom accessories to add to it. You can change the handguard, the pistol grip, the sights, the buttstock, magazines, the trigger, etc etc. There are a huge market for parts for the platform.

The next step would be to buy the main components of the rifle separate. You can buy a completed receiver ( the "lower") from one company and then the barrel assembly (the "upper") from another company. Since they are all based on the same schematics they will hook up and work just fine (for the most part)

Once you get used to that, you can purchase all the separate parts and start to build them yourself. You can get a stripped lower receiver and then buy your own trigger, pins, springs, etc and build the receiver with very simple tools (a pin punch is about the most specialized tool you need for a lower). Uppers are a little more complex and until you are more experienced most usually buy them complete and just change the handguards or sights

after that, you may want to go a little further and finish an 80% lower receiver. Its not yet considered a firearm when 80% finished so that means no FFL. There are a ton of different jigs to finish them at home with basically simple shop tools (drill press, hand held router). Want the satisfaction of building a firearm in your garage and have it work great at the range? AR15 is perfect for that.

When you are ready to build your own upper, then you get to choose your own barrels and can get into really fancy hand guards and bolt carrier groups with specialized coatings. You can try to build a very light gun using titanium parts or make one that is for distance shooting.

Once you get bored with all that you can look into different calibers. You can run almost everything from 22LR to a 50BMG on a AR15 receiver. handgun ammo? sure 458 socom? sure. belt fed 9mm upper? sure. You can even get an upper that shoots beer cans.

It just goes on and on and on. There is just an endless string of customization at all levels of skill that can happen on the AR15 platform.

Hi, thought I would chime in with a question. I'm in the same boat as billdotcom, and am new to AR-15s and am planning to build one (I used M-16A1s and M-16A2s in the Army, but was far from an expert on working on them other than cleaning.) One question I have is what is the difference between a regular AR-15 feed ramp and M4 feed ramps? Is one superior to the other or what? Thanks for the help. I'm sure I'll be back once I really get going with the project.

 

[Boboclown]

ne question I have is what is the difference between a regular AR-15 feed ramp and M4 feed ramps?

The extensions and feed ramps. M4 would be better but either works. Just try to make sure the extension and receiver match.

 

[Flopsweat]

View attachment 286087

The extensions and feed ramps. M4 would be better but either works. Just try to make sure the extension and receiver match.

It's been a while since I've seen one without M4 feed ramps. I'm tempted to say that everyone does it now, but I don't know that for a fact.

 

[Rich]

View attachment 286087

The extensions and feed ramps. M4 would be better but either works. Just try to make sure the extension and receiver match.

Thanks for the info and photos. Now I know. Have a good one.