Which AR 15 type rifle?

I don't think the issue was a question of accuracy or worthiness, but more along the lines of "If I drop some coin on something it better have a good fit and finish". I'm not sure anyone would be happy dropping $600+ to have the weapon "jiggle", regardless if it is accurate or not.

 

I've had good luck with anderson lowers

 

The biggest reasons for buying an 80% lower are, to the best of my limited knowledge (they change the rules a lot):

1) You like to build shit. You may have to machine a slot to fit the fire control group. You will have to drill holes to accept the fire control group.
2) You don't want to go through the hoops for buying a pistol. Keep in mind that if you make a pistol with less than a 16" barrel, you can never legally put a buttstock on it...it would now be an SBR, requiring you to already have the proper documentation. To be safe, don't even have a buttstock in your possession if the barrel is less than 16".
3) You don't want any documentation. There are no markings on an 80% lower. No serial number, no MFG logo...nada. Inscribe it any way you want, or not. Totally legal. You may not build it with plans to sell it...that makes you a MFG and you need a license for that.

Having said that, I'd bet "they" know/can find out who bought what and cross reference those components. So, 80% lower, short barrel and a buttstock? You could come under some scrutiny.

As far as reliability and accuracy:

Accuracy is virtually all in the upper. Consider the interface between the barrel and upper receiver. In between is a barrel extension. Those three components get locked together with a barrel nut. That's the hard parts that need no further attention, assuming they have a good fit.
The BCG (Bolt Carrier Group) is the moving part that interfaces with the barrel extension (lock lugs) and the machined sliding surfaces within the upper. That also needs a good fit. No bueno, no accuracy.

Reliability can be a fitment issue derived from incompatible or substandard parts. The quality of the lower's material can be an issue down the road. If it's not sufficiently hard, your "moving parts" can wallow out their holes, possibly leading to malfunctions. Concerning the upper, you can not skimp on the material, imo...you're threading a steel barrel nut onto aluminum. As it has to do with that connection, torque value is rated 30-80 ft/lbs. Seriously? Can't narrow it down to a more precise number? The bottom line is, screw the torque value...set it up by sight and feel. (How to- readily available.)

If you're gonna "build" your own, you should avail yourself of as much info as possible concerning the various sub-systems. Plenty of books about it.
Some of those books will tell you whether lower A fits upper B (pretty common info) and whether the BCG from MFG A will fit upper from MFG B, etc. due to individual MFG's tolerances (not so common). There's the two gas systems, piston or direct impingement (no piston), and their operating lengths - carbine, mid or rifle. Add to that, which buffer system do you need to compliment the gas system of choice. There are a number of pin retaining systems to choose from, to include no retainment other than spring pressures (doesn't know what they're doing). Spring retainment pins are simple stupid and virtually foolproof. Anti-walking pins, et al, are a solution to a problem that shouldn't exist...tho' they may be necessary depending on the trigger group you select. If your trigger group of choice requires them, my opinion is that trigger MFG shoulda gone the extra fraction of an inch to address that issue. Take down pins, ejection port cover, bolt assist...the number of components is finite but the combinations are astronomical. You'll need to get your stars aligned before you spend your money.
All that shit needs to be compatible if you want a chance at a successful build. By comparison, the actual assembling is nothing.
Brownells or Midway has a series of online videos detailing finer points of AR builds. There has to be some from other gun sites, as well. Certainly YouTube has 'em, tho' some salt may be needed.

And, not to dissuade you...I've heard that if someone else does the machining on your 80% lower, paid or not, you didn't build it and, as such, now own an illegal weapon. It's a cluster-fuck of gun laws creating the ambiguity.

 

I just sent this Q to Jed in a PM but I realized it sums up my confusion pretty succinctly, so I'm gonna pose it more widely here:

With regards to the tolerances + etc.. I get that "mil-spec" really just means "matches XYZ dimensions to ABC tolerances" and nothing more, and that that's the (pretty good) standard required by the military. Does fit between the upper and lower actually matter much beyond not rattling? I think that's what I'm most confused about, is people making a big deal about (what seems like to me) basically cosmetic fit issues. I've never really given a damn about Hotbodies vs Sharkskinz "fit", for example... but you can be damn sure I care about my valve clearances. Careful where careful matters, etc.

Is lower <-> upper fit a fairing issue, or a valve issue?

 

Another and...
The jiggle between upper and lower merely makes the gun rattle. You can put a $4 rubber plug in the lower to address it. My $700 Colt R6601 has the jiggle and my $300o AR10 has the jiggle. Both have been outfitted with the butt plug. All it does its dampen the jiggle, making the rifle quiet when handling. That's it. The jiggle is otherwise not an issue with accuracy, tho' it may lead to some wear on your take down pins and upper/lower mating surfaces.

Additional build thoughts...
The BCG has quite a few pieces, too. You can assemble from scratch or buy complete.
The whole gun is a Lego-man's dream...mix and match to your heart's content.

As a qualifier, I have never built an AR. I have disassembled/reassembled down to the last nut-n-bolt while scrutinizing fitments and wear patterns. I have absolute faith in my ability to build an amazing firearm from select parts. Buying a number of the same parts from various MFGs to determine what I feel is the "right" part(s) is beyond my tolerance level. I just want to shoot the god-damned things.
When/if I ever build, I won't be sourcing every last individual nut-n-bolt.

 

Fairing issue.

 

This is the upper/lower fit on my $3K gun, just above the logo. There's a ledge there I could stand books on. Doesn't make one bit of operating difference. What you're more concerned about with the fit is the magwell lining up with the feed ramps both longitudinally and laterally, the tail end of the upper filling the gap to the buffer tube assembly mounting area on the lower and the takedown pin. If it's all legitimate MilSpec, there shouldn't be an issue.

 

I had one that was so worn out that you never knew whether you were going to get one round or 2, 3, or 4+ It would still shoot the x ring out of a silhouette with iron sites though.

 

Awesome explanations, thanks freddy

 

Find a buddy that has one and see if he'll do a basic teardown for ya. No need to remove the barrel from the upper but everything else is easy. Study the wear marks and visualize their cause, particularly, in the upper and in/on the bolt and carrier. That did more to help me understand the machine than any book or simple cleaning ever could. People can tell you all day long how it functions but, until you see the results of wear, it's just another set of intangible words. The wear will tell you what matters and, in combination with the words describing the operational cycle, how it came to be.

 

In the mean time, YouTube's "AR15 M16 operation and functioning cycle" gives a good representation of the action, tho' it is grainy, having been produced by the Army in 1961. Newer versions depicting the cycling via animation can be helpful but they sometimes advance too quickly to easily see what's happening...search "ar15 slow motion" to get on page with relevant vids. Another one I recommend is "10 things you didn't know about the AR". The guy is pretty much on point, tho' not completely accurate with a couple statements concerning its inception.

 

There's more information about AR's out there than we'll ever need in our natural lifetimes. Just know that if you're in the market for one, do some research. I've also found some real diamonds in the rough with builds others started and didn't finish. Keep in mind that builders (big and small) know the market better than you do, and many quality builders can bring an 80% or sometimes even a complete rifle to a consumer for damn near what he would spend piecing it together on his own over an unknown amount of time.

I think someone said it before but they were spot on; AR home builders are totally GSXR guys. Some run older stuff that's just primer and go, some guys are paying for do-it-all dashboards and magnesium wheels. What they spend all depends on how "fast" they want to go.

Last guy that asked me about building an AR I gave him this advice; buy two. Buy one that's complete and at the upper middle on what you would spend on a complete gun. Take it out of the box, and shoot the shit out of it. The other, buy a matched upper/lower and a jig. As you try parts out on the complete gun and validate them, the original complete gun parts can be moved to the build. Keep doing this until you have a Unicorn and a upper mid level build. Sell one of them (NEVER DO THAT!) and start again on another platform or in another caliber. Enjoy.

 

Going the 80% route....

Fastfreddie is right. If you go that route you MUST finish it yourself. Technically you can't even use a machine that isn't yours to do the finishing work.

State laws of course vary on what is a legal weapon and such , but according to the ATF you can build any firearm you wish as long as the firearm you build doesn't violate any federal or state laws. The stickler is that YOU MUST build it.

Years ago people used to order 80%lowers and they would all go to friends house or someplace that had a mill and they would all finish their lowers and have a "build party". Doing something like was later deemed to be illegal by the ATF.

The good news is if you don't have a mill they can be finished with a drill press or even a hand drill if you buy the jigs to do it with.

Unless you just want to do the 80% for various reasons if you don't have good equipment it's way better to just buy a complete lower

 

There's also this: https://ghostgunner.net/

As if you didn't have enough options.

 

I know a few people who have looked at buying those but, for damn near $1500 you can find a used albeit worn mill. It'll do your lowers plus it'll come in handy on bike stuff among other things

 

OK, m not going thru 50+ pages...

I am thinking of picking up an AR this spring. I want to buy a simple 5.56 flat top. I'm not well versed on them, thusly I was to start entry level and see if I even like them. I know a lot of people scoff at the DPMS Oracle, but it seems to fit what I'm looking for. The M&P Sport is also in the wheel house. Any major advantage of one over the other? Not looking to shoot long range. This will just be a "getting my feet wet" gun

 

Pretty much anything in that $600 range will be fine: DPMS, M&P, Ruger, etc. Just give it a once over before you shoot. I bought a DPMS and while it's been fine ever since, the buffer tube retainer wasn't installed properly, meaning the first time I fired it, the buffer jumped out and jammed the gun in a position where I could not open it up to fix it. Outside of that it's functioned flawlessly.

 

Sportsman's Guide has a Del-Ton for $455 plus shipping. My pawn shop does transfers for $25 so I'm sure you could find the same kind of place. Or you could probably go on your local Armslist and find a decent cheap rifle. FWIW I know nothing about Del Ton.

http://www.sportsmansguide.com/prod...56x45mm-16-barrel-30-round-capacity?a=1820048

 

I wouldn't be doing my job if I didn't try to steer you toward a more expensive model.

https://dsgarms.com/armdef15

I have heard and seen that prices are coming down. And FWIW, I had a DPMS for a minute before I received my Colt. When I got them both, the difference was apparent, I thought. But, they both shot fine.

 

If I was ready to buy today, I would be very tempted to pick up the Oracle from DEGuns.net for $459. I'm not, so I figure I will do a little research and not make a knee jerk purchase.