Home AR Assembly

[RedDirtRifleman]

I’ll start this with a short version of my question, then wander around a bit with my thoughts. What skills do I need to trust that I have put together a reliable rifle that I could trust my life with, or at least to make it through a P&S quality carbine class?


I’m a nobody, just a guy that likes taking things apart and putting them together. I’ve put together 5 uppers and 4 lowers from parts. I’ve made mistakes. Skipping staking, then doing a bad job of staking, had a gas block set screw come loose.

The upper I keep as a “serious” rifle is a complete BCM upper. I do this because I knew I wasn’t putting it together as well as they could. I feel fairly confident in my lower assembly skills at this point so I moved it from a complete Aero lower to an ADM ambi lower I put together.

That said, I’m a natural tinkerer, and I like trying out different stuff just to see the differences. And to a certain extent, very rarely do I see a complete rifle or upper and think “I would be happy with that EXACT configuration.” So if I don’t want to compromise, my options are to pay someone to put a custom rifle or upper together for me or do it myself. I know I could (and should and plan to) take a class from SLR or Semper Paratus, but until that opportunity comes around, do I need to stick to using complete rifles or uppers? Or is there enough information out there that I can follow to put together quality, reliable carbines without getting into anybody’s “secret sauce”?

 

[David Mayeur]

**I'm not an armorer, just another guy who enjoys putting together his own rifles and takes pride in ensuring they are built correctly.

There is nothing wrong, per se, with assembling your own rifle. Understanding the proper assembly procedures is a good start. When you start cobbling parts together, you should ensure that you perform the necessary quality checks BEFORE you begin piecing it together. There are enough videos out there where Will Larson is talking about the things you should look for.

If you intend to use a barrel that is not dimpled, invest in the proper tools to locate the gas port and dimple the barrel. When buying an off the shelf BCG, check the headspace regardless of where it came from. Check the gas key and staking. Check everything. Even if I buy an off the shelf carbine, I check everything. QC slips happen.

Having the correct tools for the job is important. If someone tells you they can do everything properly with a hammer and pliers, they are a moron.

 

[Nate Osborne]

I agree with what was posted above. When I worked on a gun range, I would see home-built rifles go down all the time. That being said, someone with the proper tools and know-how can absolutely build a rifle that will be reliable. I have built quite a few rifles, and I will openly say that I got better as time when on, which meant that I made plenty of mistakes along the way. It sounds like you are wanting to build an AR as more of an interest into how the system works, and to increase your own personal knowledge about the gun. I think that is great, and I got into building for much the same reason.

For my own personal experience, I am very glad I didn't go out and spend serious money on high quality parts to built a 'duty grade' rifle right off the bat. I would have made mistakes that I didn't even understand were mistakes at the time, and best case turned quality parts into an unreliable rifle and worse case ruined said high quality parts.

I know that Will Larsen does a build class in addition to an armorer class. You might look at doing that, and building a good quality gun under the instruction of someone like Will. You will get the benefit of learning, while also making sure Will is there to prevent any serious errors. If you have someone local to you that is of a similar caliber, you might ask if they would be willing to walk you through a build for a small fee, or something along those lines. Most likely they have all the tools you might need, and one-on-one you could finish fairly quickly.

A bit of rambling, but just off the top of my head thoughts.

 

[Pat Tarrant]

My rule of thumb is to run at least 1000 rounds in ANY gun that's for HD use prior to it going in service. Preferably that 1000 round minimum will also have a full 2 day class as well, with no non-magazine or ammo induced failures (using known good magazines and ammo is a good idea when vetting a rifle). Any gun from any company or assembler can fail. It's best to vet it before depending on it.

While I don't advocate using a home built gun for HD, if you're using quality components, have the skill and attention to detail to assemble correctly, and then put it to thorough testing, I don't have much of an argument against. Only you can make that call, while understanding the stakes.

 

[Charles C]

I am just a civi here in NY, one issue I have is that I can not buy a duty grade rifle here in NY. even buying an upper can have issues due to safe act compliance. it's a mess here and due to the safe act and the past "gun ban" I have had to "roll my own" for some time now. thanks to knowledge I gained from P&S and other sources as well as my own experiences over the years I have come to learn my own limitations as a gun "assembler". proper staking of castle nuts and gas keys, proper dimpling of barrels for gas block set screws are a good starting point but the picking of parts that will work together and give the intended performance is where the real magic happens IMO. the most misunderstood part of the AR15 is the gas system and how it affects cycling. I consider it a 3 legged stool. gas port size and distance from the chamber and muzzle make up 1 leg. the BCG and buffer mass and spring rate are the 2nd leg and the 3rd is the ammo or more specifically the pressure of the ammo being used or intended to be used. getting the stool balanced out is the hardest part of assembling your own rifle IMO and the one most folks seem to get wrong and end up using things like adjustable gas blocks and custom BCG's when all they need is the right buffer weight or a smaller gas port. I have learned a lot from my own mistakes and bad buying decisions. I would encourage anyone who is going to assemble their own AR to study long and hard about their parts choices and realize many have made the same mistakes before, so learn from them, so you do not repeat them.