And also I was wondering are lowers considered pistols as far as Florida is concerned? Because after we drove the hour to do all the paperwork they told me that it has a 3 day wait on it, Because it could be built into a pistol.(I kinda wanted to say "yea it could be built into an sbr too. do i have to pay a tax stamp on it now?" but I realy want to be able to pick it up on thursday... )
Your dealer needs some serious remedial training when it comes to the laws regarding lowers. The Feds say you have to be 21 to buy an AR lower because the law says that an 18 year old can only buy a rifle or a shotgun and a AR lower receiver is not a rife or a shotgun. On the other hand, it certainly is not a pistol under Federal or Florida law either and your point about building an SBR out of it is right on the money. I have purchased striped AR lowers from several dealers in Central Florida and it has always been cash and carry after the background check. There is no requirement for a multiple sales report when you buy more than one bare AR receiver, like there would be with pistols. In plain english, a AR receiver is not a pistol and the only reason you can't sell it to a 18 year old is because it is not a rifle or shotgun either. No pistol means no waiting period. Period.
As far as building uppers, it is only really worth it if you plan on building more than one or are looking for a project and the satisfaction of doing it yourself. For a first build, I would recommend a barrel with the sight block already installed with pins, as it is one less thing to worry about. Just remember good pins are tapered and if you need to take the sight off and on, be sure you are driving them the correct way.
With a standard barrel nut, if you can't get it to line up in the recommended torque range, you can always file the notch a little larger on the nut, where the gas tube passes through. This is often not an option with custom nuts for free float forearms. In the most drastic cases, you will either need to get a lapping tool or trust your own skills to evenly remove some material from the barrel mount area.
Truthfully, it really is a non-issue. Over many upper builds, I have never had to do any of these, as just repeatedly tightening and loosening the nut has always brought it into range sooner or later. If you are using a steel nut, be sure and use anti-seize on the threads, as the receiver is aluminum. Grease the front of the barrel extension flange where it contacts the nut and, if the barrel nut is aluminum, grease the threads also. Moly grease is recommended.
What ever you do, make sure the gas tube is lined up as accurately as humanly possible. Check it by sliding an empty bolt carrier back and forth in the upper receiver. You should feel no resistance as the gas tube slides in and out of the gas key on the carrier. Even though problems are extremely rare, a set of GO and NO-GO gauges for checking headspace are required, if you like your fingers and eyesight.
ARs you build your self don't always work right the first time out and they don't have a warranty so, if you don't enjoy tinkering and problem solving, it may not be for you. On the other hand, if you are mechanically inclined, it is not that difficult and gives you the satisfaction of knowing your rifle inside and out.
Now I've done a bit of research and decided to go ahead and build it myself. I am probably going to pick up a dpms lower at the local shop and then order a lower parts kit and stock from midway USA. My question has to do with the upper receiver. I was going to just order a complete upper from midway, but I don't see a particular setup I like. I would like to know how hard it is to assemble your own upper and how it compares price wise to just buying the whole thing. I know I will need some basic tooling (action block,barrel wrench,and punches),but I am not quite sure what parts I will need to complete the stripped upper. Any help is appreciated !!!!
