Build verses buy your first AR?



I saw again recently someone suggesting that a first time AR15 buyer build their own AR15 so that they would be better familiar with the parts and operation.  I think a person could learn the parts and operation of a firearm just fine without building one.

By all means build a custom AR if you want too, but I highly recommend buying a good factory built AR15 for your first one.  Having built quite a few ARs myself, and seen many more built, there are all sorts of mistakes a person can make.  I’ve seen incorrectly aligned gas blocks, gas tubes, hammer springs reversed or under the trigger pin (allowing the trigger pin to walk out.  Loose barrel nuts, loose castle nuts (allowing the stock to rotate and or the buffer retainer popping out and jamming the action), and more.  The AR15 is a pretty simple weapon, but simple does not mean that you cannot mess it up.  A factory built gun will generally be assembled correctly and you will have a warranty if there are any issues.

The best thing about the AR family of weapons is the massive amount of aftermarket parts.  It can be overwhelming, and not all of it plays nice together.  With more and more companies producing parts, they are not all interchangeable.  For example, many hand guards now do not fit correctly on various billet uppers due to these aftermarket billet uppers using different dimensions then a milspec upper.

If you buy a complete rifle from a reputable manufacture, you know the parts they choose to use will work.  If you build your own, you will need to do a little research.  Sometimes trying to just buy all the best individual components will leave you with something that won’t work together.  For example, some years back a few companies were making enhanced bolt carriers.  A guy I knew purchased the LMT enhanced bolt carrier since it was supposed to be better than a standard one.  He built a SBR with it, and found it didn’t work (The LMT carrier might not have been the only issue with it, but I’m using as an example).  The LMT enhanced bolt carrier was tuned and built for a 14.5 inch barrel or longer.  This guy just saw that there was an “upgraded” part, bought it, and never realized it wouldn’t work for him.

I could go on with more examples, but if you’re going to get an AR for serious use, or if you are not very familiar with them, it is recommended you buy a factory AR15 from a reputable company.


  1. I say build as you get what you want.That said,not sure what you want shoot with friends rifles and try different rigs,that,and what are your goals for rifle,target/hunting/self defense/perhaps a all in one.

    That said,some good quality out there at very reasonable prices at moment,but,you have knowledgeable friends,I still say build your own.

    • Buying the first is the best and smartest option. Colt for instance has carpet stains on the factory floor that has forgotten more about putting AR15s together than the first time assembler will know.
      You are getting a gun that except for a rare fluke, is put together by people who make guns ready to be sent to combat and have methods that the home builder just can not match

  2. Well,after a coffee and a smoke,thought it though and say,buy a pre built AR,get good with it shooting/cleaning ect.,take out twice a month and call it done.

    Or,get a good sling for rifle,some spare mags,perhaps a red dot or optic,oh,and you will want a case.yep,the price just went up a bit,didn’t it.

    Wait,your builder friend didn’t tell you some of the other cartridge choices besides 5.56,what the hell!How about say,a .300,then only need a barreled upper,can use your lower/bcg/charge handle ect.Hmmmm….nah,so now you built another rifle,oh,don’t forget the case/sling/optics along with new lower,oh,and perhaps you might want a say 2 stage trigger,eh,not too much!

    Wait,there’s more?!6.5/6.8/7.62/.458/9m.m.,damn,maybe one more build then the extras once again,you know,case/sling/optics,wait,what tis this bi-pod you speak of,damn,gonna need a few of those!

    What do you mean you save money reloading,Ok,perhaps a single stage press/a few dies/oh,a tumbler and a few other tools,not too much!

    Wait,might as well get a 9m.m. handgun to match the 9 m.m. ammo you have already,oh,and a holster,some extra mags,some……..

    Yep,that first rifle won’t cost much!See you at the range,with what,not sure today.

    I believe lost first comment,sorry if this repeats.

  3. I tried to build my own computer, once. All I had to do was buy the bits and snap them together, but it was a fail.

    I’d say leave the custom build until after you’ve got experience with the internals of a good factory build.

  4. Definitely buy a whole gun from a company. If nothing else, at least get a whole upper and build your lower. The upper is where all the magic happens (gas, tubes, locking/unlocking, headspace…), the lower is a little more forgiving. Just be extremely sure of how to put the lower together and expect to troubleshoot it right out of the gate. And buy your upper already assembled.

  5. I agree but would add that a complete build is a valuable learning experience. Once you understand what all the bits look like and how they work together, repair, maintenance and troubleshooting become easier.

  6. When I was looking for first AR, I did actually but a lower to start a build and then priced it out and realized that a low priced AR is as cheap or often cheaper than building. So buy the first one, to get started shooting, learn what you like, and have a reference for when you do build one. At a higher price point it makes more sense to build so you get the exact parts and features you want. As an example I doubt you can get an off the shelf build with a 20″ barrel in 6.8 spc, a 2 stage trigger and a Hogue stock. Come to that, a 20″ rifle in 5.56 is rare these days.

  7. My recommendation hinges on whether a person:

    a) has experience putting together other firearms from a detailed strip-down before,

    b) has experience working in aluminum (there are some steps in assembling an AR that make no sense to people who haven’t worked with aluminum – I mean really worked with it, and understand how to use work hardening to your benefit).

    c) understands that there’s lots of optional gee-gaws for the AR-15 that are just… not necessary. Further, the builder needs to understand the issues of a gas operated semi-auto to choose anything other than the standard gas blocks, recoil buffers and recoil springs.

    d) is willing to spend the money to buy the proper tools to do the job correctly. eg, they need to buy roll pin punches, to keep the punches from slipping off the roll pins and making a mess of the receivers. A proper wrench is necessary for the barrel nut, and a proper strap wrench should be used on free-float forearms.

    For all these reasons, my usual recommendation is that a newbie buy a pre-built AR for their first AR. I did. There’s no shame in it. I’ve built every AR-15 and AR-10 I own since then, and there’s one AR in my shop that is a “shop mule,” a lab rat that is the butt of jokes and cruel, inhumane gunsmithing experiments. I wouldn’t be surprised if, at some point in the future, some shooters form a “Society for the Prevention of Cruelty to Innocent Firearms,” and they campaign to have me arrested for wanton cruelty – with that shop mule AR as “Exhibit A.”

  8. Is the “lab rat” still functional or have you done experimental things to it that make it dangerous as even scrap/recycle material?

    • Oh, no, it’s still functional.

      The barrel was a Sarco special – it doesn’t pass a bore straightness gage. It groups OK at 100 yards, but… the barrel fouls quickly. I’ve tried to lap it a bit, but I don’t think it did much good. There’s a reason why the barrel cost only $70 at Sarco – it was obviously a reject.

      When I’m trying different trigger groups, this is the lower that gets used. When I’m playing with different BCG’s, this is the upper that gets used. If I want to play with different furniture, this it the upper/lower set that gets used before they’re moved or used onto their final destination gun.


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