Share Your AR Building Wisdom

Spend the money on the tools to get the job done correctly. Even if you only build one, you'll use several of the tools again performing maintenance...and on other gun projects. Especially a roll pin starter. Get a roll pin starter or make one

Even with the right tools, use cheap insurance like masking tape when installing roll pins etc

My number 1 rule is build the AR in your head first, knowing fully what its applications will be. In other words, give it a lot of thought, a lot of research. Then, when you've got it right in your head, buy the parts.

Rule #2 - buy quality parts... at least good enough for the applications.

I've also had good luck with Stag LPKs, I've used three of their standard kits and got two good triggers, one a little too rough. I've also used three Daniel Defense LPKs with the same results, two good triggers to one that fell short. I've used one PSA kit and it had the best trigger of all kits I've used. I did try a DPMS LPK and will never use one again. Honestly though, every kit worked and gave you a milspec trigger and that's a small enough sample that I couldn't predict what anyone else will get, it's luck of the draw with LPKs. Fortunately, most other parts are predictable - go with Rule #2 and you'll be fine. And a gritty, creepy trigger can be replaced.

+1 for buying quality parts.

also, know and understand what a quality part is or isn't.

A lot of people bash things that aren't "milspec" without understanding any of why or how strong the 'lesser' options are and how high-quality they still are.

here are mine:

1. have budget in mind; not everything - even a gun you would trust your ife to - has to cost more than a used car

2. know and understand what there is about a stock AR that you like/dislike, so you know what is or isn't worth the money to replace or customize

3. the rifle needs to have an intended purpose, so you know what to build it for. You can't just buy a stainless HBAR and grip-pod and throw it on a self-defense carbine the same way you need more than an acog or eotech for a precision platform.

4. always ask for advice; it's a huge market and buying with insight is important

My biggest thing with buying/building anything is don't get something I won't be happy with later. Whether it be price, color, style, or usage. I've bought some cheap(ish) back up iron sights (magpul) to go on an AR build that was gonna be used exclusively as a scoped rifle. And I regretted it immensely, though I had no real reason to, and I never used the sights, or had any problems what so ever. It just didn't sit right with me since I didn't get the specific sighting system I wanted (they were out of stock as well as much more expensive.)

1. Don't sweat the lower too much. The accuracy is in the upper.
2. Uppers without provision for a jam button look nice and are a few oz lighter. However, even for hunting or target guns, a dust cover is useful.
3. DI has advantages and disadvantages. Adjustable gas blocks minimize the disadvantages.
4. A nice lower ambidextrous setup is a Magpul BAD Lever, BAD ASS safety (Battle Arms Development Ambidextrous Safety System) Don't let the unfortunate name dissuade you. It is a nice modular system and you can choose between left onyl, right only, or ambi and three different lever lengths on either side, And Finally a Troy ambi mag release (bought before recent events and I have not bought any Troy products since). The only one I may consider buying again as it does not interfere with the BAD Lever, even with gloved hand.
5. BCM Gunfighter charging handle is fantastic.
6. An excellent trigger is one of the most important improvements to the AR platform. The Geissele High Speed gets the lock time down to almost as fast as a bolt action.
7. An M16 BCG will give you a lifetime of worry-free service.
8. The two most combat proven gas systems lengths are 7" with a 14.5" barrel and 12" with a 20" barrel. Logically, a 16-18" barrel should use mid-length gas.
9. Light thin rails that are not sharp to the hands are nice.
10. Only spend a lot of customizing one lower. Reuse charging handle and BCG between uppers. In both cases, you can only shoot one at a time.
11. Proper tools (upper receiver vice block, armorers tool, and torque wrench at a minimum) are important.
12. On the larger .308 platform assume nothing will fit/work unless your research shows explicitly that its/works. Better to be pleasantly surprised (won't happen too often) then disappointed.

Mike

BARRELS- Don't get too hung up on barrel choice. For awhile, I waffled between the long life between of the chrome lined 4150 CMV and accuracy of the of the unlined stainless steel barrels. When I finally pulled the trigger on my PSA carbine kit, I finally settled on the stainless steel barrel for two reasons-
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1) I wanted to see if the durability of the stainless steel barrel would stand up to a heavy firing schedule and-
2) more importantly, the PSA carbine kit with the stainless steel barrel became available before the FN 4150 CMV barrel did and was at a price I could afford.

Regardless of the barrels selected, short of simple abuse, it will take a lot of rounds before a good barrel truly wears out. For a guy like me, the CMV offers little advantage in barrel life over the stainless steel and the unlined offers little advantage in accuracy over the lined barrel when using bulk ammo. There may be a half minute difference when using good ammo.
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Shot with the precision AR from a bench at 300 yards using bulk ammo. 2.5 - 3 MOA

So what it comes down to, for everyone agonizing over which barrel to choose for your general purpose carbine, choose a quality barrel, whether it's chrome lined CMV or stainless steel.

LEGOS- There are a lot of folks out there that will tell you assembling an AR is as simple as Legos. Compared to building a FAL from a kit, assembling an AR is rather simple.
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But, if you don't get the right parts, or don't understand an assembly procedure and it goes sideways on you, it can get complicated quick. No matter how easy anyone may think assembling an AR is, if you don't take time to pay attention to the details, the devil will be smiling over your shoulder.

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CONFIGURATION- Get a good quality 16" barrel and a free float tube. Heavy profile barrels aren't needed for accuracy. It's the quality of the chamber, bore and crown that counts. A 16 inch barrel gives good reach while being short enough to be truly handy. The only thing a shooter needs to do to change a carbine from CQB to a precision rig is change the sights. An SBR would be handier for house clearing and a 20" bull barrel musket will serve better picking off P-dogs way out yonder, but a shooter with a 16" carbine can do either task adequately. There is a reason why a 16" AR carbine is just about the single best selling rifle in America today.

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USE THE RIGHT TOOL- There are folks who will use Vise Grips for installing some pins. Don't do it unless you don't mind the rifle looking like it was gnawed on by the odd angry beaver. You might get away with it once or twice, but sooner or later, you'll slip and mar the finish.

Be careful installing trigger guards. It's easy to break the little ears off. Brownells sells a block that will support the opposite ear when tapping the trigger guard pin into place. Another way is to use a c-clamp. It will support the off side ear while gently pressing the pin into place.
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Use a tappet wrench to install muzzle devices. Regular wrenches are wider and when installing a muzzle device with a crush washer, the crush washer will sometimes grow in diameter as it compresses. It will trap a regular width wrench and cause marring of your parts. You can see the difference in width of the two wrenches in the photo below. I used the regular width wrench to install this Battlecomp and it boogered things up a bit. I made sure to get a set of tappet wrenches shortly after.
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A magnet can be a big help installing small pins.
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Assembling the receiver inside a large clear plastic bag can save you many hours of searching for tiny springs and pins if you should slip while trying to install them.

Use a long brass punch and masking tape when pinning the bolt release into place

If you find yourself getting tired/frustrated/hungry/thirsty, take a break

I'm not really into "name dropping" when it comes to AR builds....I shop for the best PRICE and go with what I find.

I've got quite an array of AR's but I couldn't tell you for certain "who" made "what" that went into them...they ALL function and that's what counts.

Appreciate the great tips - thanks guys!

I've also built a bunch of ARs...will be putting together another upper this week.

I've recently used the excellent Aero Precision stripped lowers. Got 'em at DOA @ $60 each, plus shipping. Like the pre-threaded channel for the takedown pin detent and spring.

AS everybody said, get the right tools.

I never use a "standard" barrel nut...always get the two-piece tubes. I like the YHM tubes with the indexing jamnut. I don't go for 8' of rails, so don't need quad rails, etc.

I NEVER buy a LPK with a a trigger...or grip, either, if I can find one without both. I use real triggers in my builds, e.g., JP, Geissele, etc.

1. The lower brand doesn't matter that much unless you are looking to impress someone or you want something outside the norm. Call it sacrilidge but I have 2 Noveske uppers...one on a Stag lower and one on an Anderson lower. Functionally it doesn't make a difference.

2. Don't buy parts twice. Don't pay for something that comes assembled or as a package unless it has everything you want. If you do you will end up with a box of parts and then you will want to build another one using those parts....only to change those out later. It's a vicious cycle. =)

3. If you're going to put money into parts, put it into the bolt carrier group, the trigger, and the barrel.

4. Don't buy junk optics. One aimpoint is better than a shoe box full of broken chinese red dots.

5. Don't buy junk optic mounts. It's no fun when you don't lap them and they damage your optic....or they won't hold zero, or return to zero if they are qd.

Don't pay extra for billet receivers. Forged receivers of 7075 are actually stronger and lighter

My last build was with a Vltor upper. It's a nice upper but not worth the extra cost IMHO
M16 bolt carriers are the only way to go.
I hate the hand guards with all the sharp rails all over the place. They are also to fat. I just used the new Midwest GenII. It's awesome.
You need the correct tools. They don't cost that much.
Rock River 2-stage triggers are a good deal. I have 3 and never had a problem.

Does name brand matter on tools? Also does anyone have a complete list of tools?

Atomd mentioned not having spare parts left over lest you want to run the very real risk of builing another ar with them. I couldn't agree more.

Plan out your build and only get what you want.

I've got an ar that was built simply because I had a spare muzzle brake, scope and buffer system though I never intended to build another.

1) YOU DON'T NEED SPECIAL TOOLS. You need to understand what the specific mechanics is for installing that part. Installing the barrel nut does not mean you torque it to a specific figure with a special tool - you are just achieving a minimum value and whether it gets nicked up in the process really means nothing in the long run.

The 85 pound figure is a maximum to prevent stripping the nose threads on the upper - you go about 30 pounds and then get the serration past the gas tube so it will slip in. IT holds the nut in a fail safe manner if it tries to back out. NOT THE TORQUE.

2) YOU BUILD THE RIFLE FOR A SPECIFIC TARGET IN THE RANGE YOU PLAN TO ENCOUNTER IT. What range, what target? A paper target at 850 yards is going to likely use a different cartridge, barrel, and optics than a live target out to 300. And neither will be all that optimal if all you are shooting in competition or dirt at a range. Economy of ammo and how you choose to supply it comes into play, too.

With the cartridge selected for the range and target, you choose the optimal length barrel. Not the fashion leader. With that barrel, you choose the optimal gas length, which is about five inches back from the muzzle. And with that you cover it with the appropriate free float or handguard needed.

A 2MOA gun will hit a 10 inch circle at 500 yards, unless you are shooting prairie dogs or mice in an open field, most North American game and two legged intruders are covered. Battle proven.

Sights on that handguard will move around by hand or sling pressure and negate it being a free float. Money wasted. If there is an iron sight up front, keep it on the barrel.

Much behind that, a flattop, any lower, any stock will do. They do not add any measurable reduction in group size, and it's entirely likely it's uneeded. However, these days, tactical style and exclusivity reign supreme, and if my rifle looks cooler than yours, then I must be, too.

Don't think it's not noticed when you show up for real shooting.

The trigger on the AR could use some slack taken out of it, and less crunchiness. 6 pounds on a field rifle is appropriate, tho, keep the 2 pounders on a benchrest or position rifle. A trigger travel screw adjuster is the #1 most common way to improve a trigger, all the better ones typically include it. In a field gun it cuts down on reset and prevents the sear creeping across a bunch of rough machining. That is about 85% of what a $100+ trigger does. Lighter springs in the AR don't actually help much, they reduce the hammer strike and increase misfires on cheap ammo. Unless you are shooting soft primers on a precision gun, it's a race gun part for a daily driver.

Using the policy of what range, what target? means you choose parts that fill the task, not the Brand that makes you cool. The overall result is a gun that at least shoots better than you, and does 85% of what you need very well. That means you don't look dumb for having a blinged out circus pony that only knows one trick. It works dynamically because all the parts are selected from a limited list of what fits the bill, not a snap shot of what's sold on the market that month.

I really cringe when I see lowers with weird selector markings and know in ten years that most of the shooting community will be laughing at the silliness. Green paint and the undead are a fad, not a firearm. Build it for what range, what target, and it won't let you down, because it will work now and twenty years from now.

Life sometimes gets in the way of our budgets, what you put together today may be all you have left in the future. Don't waste the opportunity to do it right.

Having the right tools save a lot of headaches. One tool that works awesome is the jkl mobile gun vice.

http://www.ar15news.com/2011/12/11/new-jkl-mobile-gun-vise-ar-15/

Don't start.

Because you'll never be able to stop!

I've only done a few, so bear with me:
- I've only used Stag ambi LPK's and like them, but I'm a firm believer in Geissele triggers. Thus paying for a full LPK to throw out the trigger seems a waste. I'm about to build an AR form factor 300 blk (so trendy) and am going with a JP Rifles LPK w/o trigger. Less than $40 and no throw-away parts;
- Per the prior comment, I'm a Geissele fan. Started out with a Super 3 Gun on my Stag 3GL but have since moved to Super Semi Auto Enhanced (SSA-E) triggers. Don't leave home without 'em. They are pricey but as others have noted, there are a few parts that make a difference. The trigger is one of them. After that, I pay attention to the barrel, the fore end grip, and the stock. They all matter to me;
- I'm not as young and buff as I used to me and so carrying, swinging and stabilizing a front-heavy 18" heavyweight barrel in an AR just isn't fun any more. Since I'm not in any rush to burn through boxes of ammo, I've moved to pencil barreled 14.5" (with enough of a muzzle device to make it legal) for .223's or 16" for a 300 BLK to make it light and quick in my hands. I'm happy to take my time working through a box of ammo so I don't worry about the barrel overheating and sacrificing accuracy. A quick swinging easily stabilized lightweight AR is really a pleasure in my hands;
- I don't know what many people like to do with their accumulation of successful builds, but for me, I don't want to end up with a large number of redundant, safe-space-sapping AR's. So I worry about resale value when choosing parts and constructing them. In my case, I go for consistency so that when I advertise a rifle for sale, it's not a complete Frankenstein. An all-Stag, or all-Daniel Defense model (i.e. upper and lower at least) creates more appeal from a resale value perspective. Or so I think. They may be pricier to build, that is, to accumulate parts from one AR vendor, but I think it balances out on resale value. Of course, for those who never sell, it doesn't matter at all. And I envy you.
Thx,
B

Funny you mention Colt barrel nut and Alpha rail. I installed a TRX on my Colt 6720 before the alpha rail came out so had to use Troy's proprietary barrel nut. Colt ridiculously over tightened the barrel nut which got ruined during removal. Then, the barrel nut that came with my TRX would not align within the acceptable torque range. I ordered a replacement and it went on just fine.

Having the right tools save a lot of headaches. One tool that works awesome is the jkl mobile gun vice.

Click to expand...

Colt does quite well assembling their thousands of guns a week without a fancy $220+ gun vice.

As said, a pair of cushioned vice blocks will keep the finish from being marred. That is, if it's actually any consideration. Once a gun is shot, it's used, and used guns have scratches and dings on them. A fancy set of blocks to tighten a barrel nut will not recoup the $220+ price tag.

If anything, I smell spam.

As for assembling the gun without special tools, here's a start: http://www.ar15.com/forums/t_3_4/22...__GAS_BLOCK___Step_by_step_instructions_.html

Spending money on special tools, not so much. Being competent with the tools you use is far more important. For every special tool on the market, I can point out a dozen threads where the home assembled broke, scarred, or marred his gun with them.

You can tighten the barrel nut with the lower stuck on a wooden block into the mag well and upper pinned to it. How you fasten the block down goes to the experience level of the assembler. If that is beyond their skill level, don't assemble an AR15, go back to shop class, take construction and mechanics courses, get some experience. Assembling an AR isn't rocket science, the Colt assembly line isn't filled with special jigs or gunsmiths. It's just experienced women and men who handle simple parts insertions all day long. That's one of the reasons the gun's design is so ground breaking, it was made for mass production with no special tools needed for assembly.

Unlike most civilian guns that press a barrel into a steel receiver while simultaneously setting the headspace. That is gunsmith level work and exactly why there isn't a huge "build your own AK" fan base. You can't "build" your own AK without a special press and a technical education. Setting the headspace on the AR is simple, it's a screw type micrometer adjustment with a gauge inserted in the chamber, then you pin the barrel extension in place.

The AR truly is a gun for the masses, you and I can build one. The AK is a gun for the controlling overseers, they have the tooling we don't. Exactly backwards of the popular myth.

Let's not make it more difficult than it really is. That $220+ could buy ammo, magazines, or a decent red dot scope. The jig vise will just sit in a box on a shelf until you spend another $1000 to assemble the second gun.