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Old June 2, 2014, 06:26 AM   #1
8MM Mauser
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A little guidance - Building an AR.

Hello again all. The inevitable has finally happened to me! I have been bitten by the AR bug. Furthermore, I have decided that I want to "build" one if for no other reason than shelling out $1000 all at once for a rifle would be hard to swallow. I do not intend on actually starting until probably next year (unless my wife catches by bday and christmas hints). That said, I am already beginning to try and get a sense of what I want to do.

I would like to buy a complete upper, that much I know; assembling a lower looks simple enough, but I find the idea of figuring out headspacing and all that beyond my meager abilities. This upper from STAG is what I am hoping to get with the "plus package." The plus package upgrades the barrel to 1/7 twist, 4150 steel and the semi auto bolt carrier to an M16 bolt carrier; the bolt and barrel are HP/MP tested. All that for $610? and as I understand it STAG's parent company make a lot of parts for Colt and FN, so I feel good about the quality of parts.

Lower's are where I get a little lost. I feel unsure as to what parts will be most important to improved function. There are things like this from PSA for $150. With that I could attach it to the upper and be done; but am I getting something that's worth it? For $100-ish I could get a PSA stripped lower and this kit from Daniel Defense. I would still need a buttstock and buffer tube and... something else? It's hard for me to tell. Even needing all those parts though, I would still only be in for like $100 than the complete PSA lower, and DD is a respected manufacturer. I would still be saving some money over buying a complete rifle and I would be getting some quality parts.

The point is though... I need guidance. Does this decision make sense? I would like to get the most bang for my buck, but I really want a quality rifle too. It would be for the range and perhaps an HD weapon once it proved itself. I know I could save a little longer or a little bit more and buy a complete rifle, but I want to spread the cost and want the experience of assembling it and knowing the gun well. I am hoping that I can save money wherever it will least affect quality/function.

Thanks for any advice!
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Old June 2, 2014, 07:11 AM   #2
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The best advice I can give you is "do not buy one built". Get a stripped lower. The reason is that you will want to select the trigger, maybe a safety lever, and maybe a heavy buffer and/or buffer spring. So you end up spending money on the parts you want later instead of just getting what you want the 1st time. Building a lower is easier than changing a tire on a car, so don't be intimidated at all. Get a stripped lower and built it exactly as YOU want it instead of getting what someone wants to sell you.
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Old June 2, 2014, 07:38 AM   #3
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I built my AR. First, it's usually not cheaper, you buy the parts at retail and wind up paying shipping on all the separate orders. A built gun always offers most of the net savings from the makers buying in bulk and passing it along.

Since there is labor, add about an hour of your time to assess the cost of that, and buying the parts means no tax a whole gun is required to pay.

Building your own does mean picking your parts with an eye for what you want them to do. The functional reality is that we should pick the cartridge first - that's all the gun does, support igniting the cartridge and launching the bullet. We shoot at specific targets to a maximum range - specify them. If it paper out to 500m, as oppose to live targets out to 150m, the cartridge chosen could be tailored for the job.

That helps determine barrel length, which selects the proper gas port location. From there, it gets mounted into an upper, flattops are more useful because of the optical mounts being easy to use with a large variety available. The lower gets attached, about the best thing to do is get a trigger with a set screw slack adjustment. Weak springs in the AR to reduce trigger pull also reduce hammer strike, and expensive drop in triggers might be nice, but 80% of what they do is because of an adjustable slack screw. A $200 trigger can not and will not make a gun with poor barrel a great shooter. Better to put the money in the barrel first, then upgrade the trigger later.

Stocks and grips to suit, same story - all they do is hold the gun up to your shoulder, there is no MOA improvement in accuracy that anyone can document on the range or test lab. But you can get what you want.

Most uppers and lowers are a commodity item, there are actually a limited number of forges, a lot of machine shops, and plenty who recommend Brands based more on the style of the rollmark than any special reason. Focus the build on the cartridge, barrel, and optic, and the gun will turn out well.
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Old June 2, 2014, 12:57 PM   #4
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If you purchase a complete upper (with BCG) you will have a unit that is headspaced, Stag is great ...PSA also but buy premium. The lower is easy if you get a parts kit sans the FCG then buy an ALG ACT trigger/hammer (FCG) for $64 and you will have a super shooting rifle. Make sure you buy a receiver extension that is milspec in size and material. Stock is your choice I like Magpul stuff...CTR and MOE PLUS grip is a good but inexpensive combo and the stock will lock out most of the slop.
Top it off with fixed Troy or DD sights and you are ready to roll in the sand.
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Old June 2, 2014, 01:59 PM   #5
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If it was me I'd buy a complete mid length lightweight upper from BCM without a bolt carrier group. A spikes tactical hp/mp tested bcg. Bcm charging handle. A stripped lower, mil spec buffer tube with an h2 buffer, PSA or spikes lower parts kit. Get a magpul stock and handguard and your set.
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Old June 2, 2014, 02:37 PM   #6
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G&R Tactical is selling complete Colt 6920 uppers for $627. Other vendors may be selling them too. I've had several Stags, liked them all, and still have one self-built that has a lot of Stag parts. But for another $17, I'd go Colt.
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Old June 2, 2014, 10:21 PM   #7
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Quote:
G&R Tactical is selling complete Colt 6920 uppers for $627. Other vendors may be selling them too. I've had several Stags, liked them all, and still have one self-built that has a lot of Stag parts. But for another $17, I'd go Colt.
Thanks for that tip! For a few extra bucks the Colt would definitely be worth it!
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Old June 2, 2014, 10:24 PM   #8
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Quote:
I built my AR. First, it's usually not cheaper, you buy the parts at retail and wind up paying shipping on all the separate orders. A built gun always offers most of the net savings from the makers buying in bulk and passing it along.

Since there is labor, add about an hour of your time to assess the cost of that, and buying the parts means no tax a whole gun is required to pay.

Building your own does mean picking your parts with an eye for what you want them to do. The functional reality is that we should pick the cartridge first - that's all the gun does, support igniting the cartridge and launching the bullet. We shoot at specific targets to a maximum range - specify them. If it paper out to 500m, as oppose to live targets out to 150m, the cartridge chosen could be tailored for the job.

That helps determine barrel length, which selects the proper gas port location. From there, it gets mounted into an upper, flattops are more useful because of the optical mounts being easy to use with a large variety available. The lower gets attached, about the best thing to do is get a trigger with a set screw slack adjustment. Weak springs in the AR to reduce trigger pull also reduce hammer strike, and expensive drop in triggers might be nice, but 80% of what they do is because of an adjustable slack screw. A $200 trigger can not and will not make a gun with poor barrel a great shooter. Better to put the money in the barrel first, then upgrade the trigger later.

Stocks and grips to suit, same story - all they do is hold the gun up to your shoulder, there is no MOA improvement in accuracy that anyone can document on the range or test lab. But you can get what you want.

Most uppers and lowers are a commodity item, there are actually a limited number of forges, a lot of machine shops, and plenty who recommend Brands based more on the style of the rollmark than any special reason. Focus the build on the cartridge, barrel, and optic, and the gun will turn out well.
I don't expect it to be cheaper, so much as less of an expense at any one given time. It's much easier to swallow $650-$675 for an upper and later $100 here, $150 there for parts than $1000 for a complete rifle.

Your advice is quite sound I think, thank you! I will keep what you said here in mind as I work through what I want. The barrel is definitely something to focus on.
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Old June 2, 2014, 10:25 PM   #9
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Quote:
The best advice I can give you is "do not buy one built". Get a stripped lower. The reason is that you will want to select the trigger, maybe a safety lever, and maybe a heavy buffer and/or buffer spring. So you end up spending money on the parts you want later instead of just getting what you want the 1st time. Building a lower is easier than changing a tire on a car, so don't be intimidated at all. Get a stripped lower and built it exactly as YOU want it instead of getting what someone wants to sell you.
Thanks! That is more or less my plan. I really want something that is exactly how I want it.
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Old June 2, 2014, 10:26 PM   #10
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Quote:
If you purchase a complete upper (with BCG) you will have a unit that is headspaced, Stag is great ...PSA also but buy premium. The lower is easy if you get a parts kit sans the FCG then buy an ALG ACT trigger/hammer (FCG) for $64 and you will have a super shooting rifle. Make sure you buy a receiver extension that is milspec in size and material. Stock is your choice I like Magpul stuff...CTR and MOE PLUS grip is a good but inexpensive combo and the stock will lock out most of the slop.
Top it off with fixed Troy or DD sights and you are ready to roll in the sand.
Quote:
If it was me I'd buy a complete mid length lightweight upper from BCM without a bolt carrier group. A spikes tactical hp/mp tested bcg. Bcm charging handle. A stripped lower, mil spec buffer tube with an h2 buffer, PSA or spikes lower parts kit. Get a magpul stock and handguard and your set.
Thanks for the guidance! I will look into it all!
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Old June 3, 2014, 02:51 AM   #11
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Whoever suggested the Colt upper, i'd probably go that way if i was in your boat. As for the lower, getting the ALG ACT trigger/hammer is a great buy. Then go with an LPK without the trigger group(obviously). As for a buffer tube/buffer/stock.......go with what you want there. I don't see the need to upgrade to a stronger buffer because i don't think the .223 really kicks enough to justify it. Find a stock you like, and go with that. Also, don't forget about optics, but that's much farther down the road.

I was in the same boat you were about 2 years ago. I didn't want to pay for everything at once, and i wanted to build mine. I took around 2 years(the sandy hook scare made it a lot more difficult to find parts) You'll be pleasantly surprised how easy it is.
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Old June 3, 2014, 05:34 AM   #12
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Also look into the ALG QMS trigger ($45 every place I've seen it). It may fit your needs/budget better.

As for buffers, here's the Cliff's Notes version of why the buffer is so important.

When a round goes off, the case stretches to the dimensions of the chamber. At that point, there's tension between the chamber and the case. If extraction happens too early, the rearward pull of the extractor claw on the case rim can rip off the rim due to that tension. Or, a weak extractor claw will slip over the rim and leave the case in the chamber.

If extraction happens too late, there might not be enough power to fully cycle the bolt, leading to short stroking.

The weight of the buffer, along with the recoil spring (and to a lesser degree the bolt carrier), provide resistance to the force of the gas used to cycle the bolt. A too-light buffer can cause early extraction. A too-heavy buffer can cause late extraction.

When you throw underpowered rounds into the equation, you can end up with short stroking because there's not enough power to fully cycle the bolt. When you throw Russian steel-cased ammo into the equation, you have rounds that tend to be underpowered plus cases that generally don't stretch to the dimensions of the chamber, which allows residue to blow back into the chamber and around the case.

Lots of people shoot Russian steel-cased ammo without any issues. Personally, I shoot my reloads, so I don't have a need for the stuff, but I wouldn't be overly adverse to it. I'd just use a different (lighter) buffer to ensure proper cycling. I do have another, non-AR gun that I use Russian steel-cased ammo in, but only for plinking. In addition to lesser case expansion and an increase in residue, the stuff has a tendency toward dud primers. I also have factory brass-cased ammo for that gun if I ever need it for anything serious.

Of course, others hate the stuff and point out some of the functional problems. They have a point - the Russian steel-cased ammo certainly isn't ideal - but I suspect most of the problems they have - aside from dud primers - is related to how they are set up.

In sum, test your buffer against the lowest-powered ammo you intend to use. Use the heaviest buffer that will still allow that ammo to function properly. Because buffers are typically easy to disassemble (just pay attention to how the internal weights and rubber dampeners are arranged), I buy H2 buffers and then switch out the titanium weights with a carbine buffer if need be. That way, I have my choice of carbine, H, or H2 buffer.
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Old June 3, 2014, 06:02 AM   #13
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Thanks for the tip, i'll look into those parts. Sounds like ALG is the way to go for triggers.
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Old June 3, 2014, 09:10 AM   #14
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If you look to ALG Defense for a trigger, the ACT is ni boron and ni teflon coated for one smooth $64 trigger. I have spent over $200 for some of my FCG's and they are not much better than the ALG......and NO I do not have stock in the company :-)
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Old June 3, 2014, 01:34 PM   #15
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If you are patient, you can build a rifle and do well on price. Watch for sales and free shipping. As for headspacing, that is already set when the barrel maker attatches the extension. Imo, building an upper is no harder than building a lower. Aside from spreading out the cost, the big advantage to building is you get exactly what you want and don't have to waste money upgrading.

There is no way I would have ended up with mine if I had to buy it all at once but a few parts at a time, I could afford what I wanted.

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Old June 4, 2014, 06:28 AM   #16
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SRH78:

That is a sweet looking rifle! Thanks for the story. Part of the reason I am doing this is to help myself build discipline and patience, and I intend to be very patient. My plan is to have it built by the time I am 30. I am turning 27 in a few months.

Plus there are at least two other (much cheaper) firearms I intend to get in that same timeframe. So not even all my "gun money" will go towards the AR necessarily. Right now my only rifle is a great shooting 8MM. It is a good gun but expensive to shoot; even reloading components are a bear to find were I live (only Cabela's carries the right bullets and only occasionally are they in stock) unless you are willing to pay excessive shipping. So I will almost certainly make a .22LR rifle of some flavor my next "big" purchase.

Part of my plan is to sell off some stuff I don't need anymore to help finance AR parts. So if say, I successfully sell off my beat-up old shotgun I'll grab myself some lower parts. On my next work bonus I might try to grab that Colt upper mentioned above. Not sure how a Colt upper will look hooked to a PSA lower but oh well.

Thinking about it, I bet I could have all the parts by the end of next year if I budgeted correctly: $630-ish for the upper, $50-$100 for the stripped lower, $60 for a trigger, $40-60 for a LPK, probably another $100 on the buttstock and buffer. (this last part is what I feel I understand the least about so far)

Of course this kit from Armalite is out there too.

The problem I am finding with AR's is that there might actually be too many choices!
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Old June 4, 2014, 06:30 AM   #17
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Oh and an optic of some flavor would have to come later as well. Irons would be fine while I saved up.

I have no clue on optics for an AR either. I think I want a red dot.
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Old June 4, 2014, 07:06 PM   #18
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You may also want to visit m4carbine.net. Many of the guys over there use ARs and/or M4s for a living. Lots of good info there. Check out the Custom Build and AR Technical Discussion forums. In fact, before doing that, check out the posted Sticky Threads in the AR General Discussion and AR Technical Discussion forums. Lots of info but well worth the time spent. Bill Alexander and Iraqgunz know their stuff (as do a lot of others, but those two are the best of the bunch).
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Old June 5, 2014, 05:35 AM   #19
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Thanks for that tip man! Maybe I'll even make some new friends.
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Old June 5, 2014, 04:55 PM   #20
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If I did want to take on building (part of) an upper what besides a hand-guard would be missing from this. It is $628 with a BCG and it lists this:

•M4 Feed Ramp Barrel Extension
• M4 Feed Ramp Flat Top Receiver
• T-Marked Upper Receivers
• USGI 1/7 Twist Rates
• USGI 5.56 NATO Chambers
• Mil-Spec 11595E - Certified Barrel Steel (CMV)
• Chrome Lined Bore and Chamber
• Manganese Phosphate Barrel Finish
• Mil-Spec F-Marked Forged Front Sights
• USGI Government Profile Barrels
• HPT (High Pressure Test) Barrels
• MPI (Magnetic Particle Inspected) Barrels

All I see missing is a charging handle, a rear sight and a hand-guard. Am I missing something? I feel like I am.

I like BCM, and I like that this has a rifle length gas system and 20" barrel.
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Last edited by 8MM Mauser; June 5, 2014 at 05:01 PM.
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Old June 5, 2014, 07:00 PM   #21
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You'll also need tools.

I don't have time at the moment for a comprehensive list, but basically you'll need:
  1. An action block (I prefer the full "clamshell" type).
  2. A torque wrench that goes at least to 80 foot-pounds.
  3. The "adapter" wrench that goes on the torque wrench (I can't remember what it's called).
  4. Good instructions (lots of choices) + the military tech manual, which I believe is tm9-1005-319-23 (Google that and it should pop up the tech manual).
  5. Punches appropriate for use on roll pins.
  6. Etc.

This might help too: http://www.midwayusa.com/general.mvc...ld-ar-15-rifle
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Old June 6, 2014, 07:29 AM   #22
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Thanks, I've got 2,3,5 and hopefully 6. 1 and 4 can be acquired without too much pain I think.
I could probably do with a better set of punches anyway really.

I've started and excel document with a list of parts, a list of tools and a list of "other" things I will need to approach this project. I also have several AR parts diagrams as well as links to guides, manuals, and a list of different manufacturers and the companies thy but there parts from.
This project is bigger than I thought it would be and there is a LOT to learn.
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Old June 6, 2014, 08:10 AM   #23
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Never mind
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Old June 6, 2014, 10:48 AM   #24
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8MM, How are you fixed for ammo? I started laying it in about the time I decided to do my first build.

Have heard about folks all excited when they are able to attach their upper so they can head to the range only to realize they don't have ammo
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Old June 6, 2014, 05:28 PM   #25
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That is a good point! After I purchased my first defensive pistol I realized I hadn't budgeted for ammo. I sold a table on craigslist to finance practice.

I should start soon buying up .223 when I see a deal.

Wise advice sir!
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