AR15build - Do people only machine the lowers and sub the rest?

PurpLev

PurpLev

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I am considering a future AR build, at the point where I'm still trying to figure out if it's worth it, and how involved it would be (yes - I can put all the parts together if I purchased them (done that before once or twice...), but am more interested in making as much of it in the shop which is what the consideration is all about). Browsing all the forums, it seems the only parts people discuss RE machining is the lower casting.

1. of you people that build ARs, do you machine any of the other components? or is it just the lower that gets to be machined (80%, 0%) ?
2. if so, what is the benefit of machining your own lower (considering cost of all other parts, the savings on machining your own lower seems insignificant to a certain degree)?
3. If you machine more than just the lower - what other components do you machine? is there a good reference to check for following through?

Thanks,
Sharon
 
The lower requires paper work as it carries the serial # of the firearm. Build you're own and assemble a rifle and you have a gun with no serial #. Used to be illegal, probably still is. I gave up my ffl years ago so I haven't kept up on the laws. If the upper carried the serial number they would all be building those. with a lower costing around $100.00 machining one would make no sense, but would be a good learning experience.
 
Gun guy here. Lowers are made at home because it's the only part than needs to go through an FFL normally. It's legal almost everywhere in the US for an individual to make a gun for themselves with no marking requirements of any kind as long as they are not making with intent to sell. I've got 11 ARs, including a registered full auto M16, as well as a mill and a lathe and I've never bothered to do an 80% lower because it's simply not worth the effort to me. Doing an 80% would really just be a fun exercise or a way to legally obtain an AR without having to fill out Amy government forms if you feel the need to do so.
 
Thanks - that makes sense as I do know the lowers are serialized and are tracked.

any advocates for making your own? any other reasons other than lack of paperwork one should machine their own? (I didn't see anyone make any lowers with unique features that would have any benefits over purchased ones, so I guess custom features on lowers isn't one of the major attractions)?
 
Well an enterprising machinist could try and improve on the design by designing an ambi mag release and bolt stop release like mega arms does with their billet lowers.
 
PurpLev said:
I am considering a future AR build, at the point where I'm still trying to figure out if it's worth it, and how involved it would be (yes - I can put all the parts together if I purchased them (done that before once or twice...), but am more interested in making as much of it in the shop which is what the consideration is all about). Browsing all the forums, it seems the only parts people discuss RE machining is the lower casting.

1. of you people that build ARs, do you machine any of the other components? or is it just the lower that gets to be machined (80%, 0%) ?
2. if so, what is the benefit of machining your own lower (considering cost of all other parts, the savings on machining your own lower seems insignificant to a certain degree)?
3. If you machine more than just the lower - what other components do you machine? is there a good reference to check for following through?

Thanks,
Sharon
Click to expand...

1. I machine the $20 forged blanks sourced from RGuns other listing. For barrels, most of the time, I will buy a uber-heavy rifle length bull barrel and profile it to the diameter and length needed. I personally prefer the rifle length gas system.
2. There is no savings on machining your own receiver. At a minimum, you will spend over $150 in tooling, work holding you will not have on hand. The 1-3/16x16 tap for the buffer tube is $100. To get one lower Type III anodized made from 7075 alloy will cost $75 to start and $6 per square inch after that. The largest benefits are education, sense of accomplishment, and joy of making it yourself. If you do make it, you can NEVER sell it. It can be passed down through your immediate family or the members of your Gun Trust (something you really want to have for all firearms, not just NFA items).
3. I make the lowers, rings, barrel profiles, Picatinny scope bases with forward cant, and front sight bases for globe front sights.

The best reference to what it takes to machine a forged blank is the Ray-Vin AR-15 Machining Guide. It contains everything, step by step, including the tools and work holding required. You can find all the information here: http://arlower.ray-vin.com/ar15/ray%20brandens%20complete%20ar%2015%20build.pdf
 
Thanks again.

like I mentioned earlier - ambi controls would be a candidate for custom made lower - but I haven't seen anyone actually doing that from browsing all the online lower threads (I am sure someone does, just nothing that I've seen as of yet).

From the sound of it - for work holding, anodizing (unless home made - which I have done for 6061), taps and the likes it would actually cost MORE to make a lower than to purchase one. and the first one will take the biggest hit (like firsts always do)

thanks for the info and food for thought
 
Well I'd look at the tooling expense as more of a pro as good excuse to get more tooling than a con :D
 
pestilence, I do agree. I am very fortunately my Lady loves tools as much as I. She has never baulked at making any smart tool or machine choice. She bought me a Grizzly G0709 lathe to do barrel and suppressor work.

PurpLev, it is very expensive to make one completed lower receiver than purchasing one. If are wanting to add ambidextrous controls, the only items which requires additional machining is the bolt release. There are drop-in magazine releases made by Troy, Knights, and Norgon. The only ambidextrous control I put on the rifles are the selector. Several vendors make these or you can just add the lever to the right side. If my 10-year daughter can drive every rifle in the house with all the same control, that is good enough for me.

To try and break in cost compared to an OTC version, you would need to make 15 units, all anodized at the same time. 7075 anodizing is 20% more expensive compared to 6061 due to the copper in the alloy. Aero Precision, who is one of the largest manufacturers of upper and lower receivers, can make them within their lights-out machining facility complete with anodizing for $40 each wholesale (1 million unit purchase price).
 
Personally I don't see any thing wrong using a 80% receiver, I've built one just for the fun of it. You don't need a lot of extra tooling you should have every thing needed if you machine.

I did purchase one of the blanks and after I check into the tooling to do one I figured it was to much. It is still laying around here one day I'll find a use for the Al. casting.

I've got a M1 Grand kit in 308 with all the new wood and I new barrel and every thing I need except a receiver. I also know that I'll have to get a receiver through a FFL dealer.

I also have a M1 Carbine receiver that dies have a serial number on it and I'll get around to building that I hope.

Paul
 
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