[trentinator777]

I know a guy who builds AR-15s and m4s I was wondering if I could build one myself and what would be the cheapest, and most effective way to get one

[robocop10mm]

Building one is little more than assembling one. There is no fitting required if using the proper parts. There are a few things that are tricky without the proper tools, though.

[bige91603]

I recently started to do the same thing. A little investing in the proper tools and you're set

[silverado113]

Tread carefully here. If you are talking about assembling them for resale you will need a manufacturers FFL, a business, etc. If you want to build them from scratch you will need a manufacturers FFL, etc (see above). If you want to assemble one for personal use go ahead. If they are true M4s you'll need an SOT stamp with your manufacturers FFL and some other items. I think a little more clarification on your intent would help.

[bige91603]

I build for personal use but if someone offers to buy it I am willing. Would you still need a ffl to do gunsmithing/assembly but personally never owning any of the parts esp.the lower?

[ArmedCitizen011]

I am enrolled in gunsmithing school, and in order to repair, build, or modify firearms that are not your personal firearms you must have an ffl.

[silverado113]

Originally Posted by bige91603

I build for personal use but if someone offers to buy it I am willing. Would you still need a ffl to do gunsmithing/assembly but personally never owning any of the parts esp.the lower?

On personal builds that someone offers to purchase, no. However you are treading a very fine line, if the ATF catches wind that you are doing it to "attempt to make a livelihood". On gunsmithing, according to the ATF you do. Think of it this way, I'm a customer/friend/whatever and I come to you with all my parts and ask you to put them together for me. While that is considered gunsmithing and requires an A&D book from my understanding. What happens if I'm a dummy and load a hot round and blow up my rifle along with my hand. You know who I'm coming after? The guy who built it. Always CYA=Cover Your A$$

[danf_fl]

From the BATF website. There are references you REALLY want to check:

9. May I lawfully make a firearm for my own personal use, provided it is not being made for resale?
Firearms may be lawfully made by persons who do not hold a manufacturer’s license under the GCA provided they are not for sale or distribution and the maker is not prohibited from receiving or possessing firearms. However, a person is prohibited from assembling a non-sporting semiautomatic rifle or shotgun from 10 or more imported parts, as set forth in regulations in 27 C.F.R. 478.39. In addition, the making of an NFA firearm requires a tax payment and advance approval by ATF. An application to make a machinegun will not be approved unless documentation is submitted showing that the firearm is being made for the official use of a Federal, State, or local government agency (18 U.S.C. § 922(o),(r); 26 U.S.C. § 5822; 27 C.F.R. §§ 478.39, 479.62, and 479.105).

[trentinator777]

I do not plan on selling anything I make or assemble, but I would like to know how much it's going to cost me.

[danf_fl]

I've done one. The bill came out to under $600.
That was with stripped lower, a "complete" kit, sights, and mags.