M4 build thread


Verified Alarmist
SOF Support
Sep 4, 2008
Somewhere in the IRQ
M4 build thread (Range Report 08 NOV 08)

I have built a number of AR's / M4's in the recent past few years. Almost ALL of them started as a bare lower, and pieced together according to the requestor's needs.

Now, I wanted to open discussion on my current project. I am deploying to the box in a month, and my personal AR's are all set up for me... one has an EOTech on it, the other has an ACOG.

This new rifle is for the HH6. This is her rifle, and I am setting it up for her. I purchased a box stock Smith and Wesson M&P 15. It is a traditional M4, with the removable A3 type carrying handle / sight rail. It has the traditional front sights, with the shorty round plastic handguards.

The trigger, out of the box was QUITE impressive. The finish and fit were equally impressive. Over all, this is one VERY nice AR.

The 6 position stock on the S&W is quality kit, but she likes the MAGPUL I have on my shorty.

So, if you were to build up a carbine length M4, how would you do it? What rails would you use? Would you keep the standard front sights or put a low profile gas block and full floated rails on it? What type of pistol grip do you like? Stock? Etc..

This rifle will eventually wear an EOTech, but for now, she's sticking with iron sights.

I will post some pictures of her shooting this weekend...

I look forward to your input, and this will be a good discussion thread.

As one who is looking to put together an AR I'm quite interested in this thread. I'm sure I'm not the only one.

So, to our resident gun nuts...start typing bitches. At combat speed.
Yeah, this will be an interesting thread! Thanks GSXR!

I have always leaned towards the long shooters and never did an M-4 variant. I am getting ready to do that now as well! So maybe I can get some advice on how to build my CQB shorty! If you don't mind the hitch hicker!?!
I have two AR's already that I have built... this one, is a bit different. I started by ordering a complete Smith and Wesson M&P 15, and plan to just use "add on" parts for it. Everything added will be function, over form.

My shorty AR has a Timney trigger in it, and I really like it. But, this Smith has such a nice trigger out of the box, I may not do anything with it. I will put an ambi selector switch on it, and an extended magazine release, due to my HH6 has pretty small hands. She also shoots ambidextrous.

I am keeping the iron sights for now, because I am teaching her the basics of how to go from mechanical zero, to battle sight zero for her, and repeat it. Once she has that down, I will mount an EOTech on it, since she loves my 552.

I won't be hanging a PEQ on it, or any other form of laser aiming divice, so a long, fully floated forearm rail is wasted money, and wasted space.

I will, however, mount a light... so I do need rails. I am considering the Troy Industries 7" MRF-DI, since it is a drop in rail, for a carbine length gas tube. It allows to bridge mount the optics, which gives me space for a magnifier behind the EOTech, or to mount a BUIS behind later down the road.



As for rear stocks... I am HUGELY impressed with the stock S&W piece. While not as sturdy as my MAGPUL, it is impressive over some I have seen. It is a true six position adjustable stock, and she seems to like it. Therefore I may not mess with it yet.

Vertical forgrips... love em or leave em, she likes them. I for one, do not use them, for I use my non firing hand cupped right in front of the magwell. which allows me to transition to magazine changes quickly. I'm not a fan of pressure switches, so I am at odds of how to do this with the surefire light I have to add to this rifle.

Pistol grips... I have a Tango Down grip on my shorty, and I like it. But, she seems to be more inclined to the Ergo Battle grips. She likes the angle and feel.

Now, for charging handles... I run a PRI Gas Buster on my shorty, since that is the rifle I run a can on. It keeps gas and grime out of my eyes, when shooting it suppressed.

http://www.bravocompanyusa.com/PRI-Gas-Buster-Charging-Handle-p/pri m84 gb.htm


The stock Smith charging handle is Mil-Spec, and for me, it's comfortable. But, to give her something more substantial to grab... I like the tactical latch from Badger Oridnance...

http://www.bravocompanyusa.com/Badger-Tactical-Latch-p/tac latch - badger1.htm


Anyway... those are my thoughts. I am looking forward to input from you guys / gals. Give me some suggestions, and help me build her rifle. I will take pictures as I go along, and show you the changes as it evolves...

Stocks: LMT SOPMOD, Vltor EMOD, Magpul UBR or CTR. I prefer the SOPMOD or Vltor EMOD. Top two stocks with the go-fast guy's

Rail Systems: Daniel Defense "Omega" rail. No gunsmith required, free float, mil-spec'd and hard piece of kit. Others are of course Knights RIS and RAS, Yankee Hill Machine (YHM) lightweight rail systems. LaRue Tactical is probably one of the best also but requires the removal of the FSB and gas tube, barrel nut, delta ring etc. Easy if you've got the tools and bench blocks. Same goes for the Knights stuff.

Grips: Mag Pul MIAD with the Enhanced trigger gaurd. Ergo grip, Tango Down battle grip, etc.

BUIS: Trop flip ups, Midwest Industries flip ups (MI), A.R.M.S LP40, LMT A2 rear style sight and the Matech 600 meter flip up.

Yankee Hill Machine makes a great front sight gas block in integrated flip up front sight.

I'll think of more later. ;)
Okay, I had to star somewhere so I got my new M-4.

Something to build on!!!

I built my first M4gery. Here's a picture from the initial build, since then I've added the Daniel Defense 7.0 rail system, a KAC vertical grip, single point sling adapter/sling, Viking offset light mount w/ G20 Nitrolon, and an Aimpoint 3x magnifier w/ LaRue mount.


Upper and Lower receivers: Rock River
Aimpoint Comp ML3 mounted with ARMS #22M68/#22M68 Cantilever
Colt Bayonet
buffalo61 said:
If I was going to build an AR15 or an M-4 from the lower reciever up, what would be the best site to go for parts/best prices. I have been doing a little research and noticed there are a ton of them out there.

Also, would it be better to buy a complete one and modify it to my needs? This is going to be the first time I buy/build an AR, so I want to get it right the first time.

I have been taking the advice for equipment from this thread and a couple of others and I think I have an idea of what I want, I just don't know what lower reciever I want to start with.

Personally I'd go with an LMT Defender lower or the Rock River Arms lower with the two stage NM trigger. You can find for about $450 or if you want standard stage trigger you can find RRA lowers for about $300. Good stuff.
rock river makes good stuff. My armalite is good enough for what I need. Make sure get a 'tactical" upper with forward assist, dust cover, etc. The Sporting models that don't have that are going to get dirty nasty and when it DOES foul you're fucked because it doesn't have a forward assist to get that round fully seated so you can save your ass.

Grips/stocks are personal choice, I like the pachmeyer for "aggressive" design rifles, your choice as to comfort. Each buttstock has its advantages and disadvantages.

Optics, think about what you are going to do.. nowadays a red dot is fine all the way to 600m especially with a magnifier behind it to bolster your visual capability.

Lights, again personal choice, I have the thunder ranch setup with mine.. i can pull the light off of the mount if i need a handheld light...

Iron Sights, I went with flipup just so they're out of the frigging way for using whatever optic gets placed on the weapon. They're reliable and accurate enough to hit out to 300+, we'd hit at 500 with our rear flipdowns with no issues.
Just remember that LMT, Colt, and RRA are 7075TI aluminum lowers and uppers while others are a lesser 6061 aluminum. To me it makes a big difference in quality and reliability of your weapon system.

Just something to think about.
Just remember that LMT, Colt, and RRA are 7075TI aluminum lowers and uppers while others are a lesser 6061 aluminum. To me it makes a big difference in quality and reliability of your weapon system.

Just something to think about.

Yeah, I want a RRA or a LMT. I have a COLT HBAR setup for International Calling!

My Bushmaster was also a V-Match at least until today anyhow!
Hey Folks,
I don't know if these folks are any good, but I thought I'd pass along the info/prices.
Take it as you will, but I imagine time is running out (Inaugeration in January) so I figured I'd pass the info:
Don't know about quality, but hear the S&W's are good. Take it as you will.
Dear Ty,
It took a couple of days, but we have managed to stabilize our replacement cost on our best selling ARs and AKs. As reported on ABCs Nightline tonight, distributors nationwide raised prices as much as 200 percent on Wednesday. Our website prices are updated hourly 24/7 to reflect our current replacement cost on each make/model. We have since contacted each of our distributors and secured our reorder costs through the end of this year.

For example, the very popular Doublestar Mil-Spec M4 A3 .223 has returned to the original price of $699 Delivered.

Also back to $699 Delivered, the Century International Arms Model RI965X Black Synthetic 223.

Earlier this week we ordered just about every AR we could get our hands on. As a result, we have hundreds of ARs enroute to us now via UPS. We are offering reserve orders, first come -first serve, on some of these incoming firearms, like the Smith & Wesson M&P 15R 5.45X39, Model 811011 for $879 Delivered.
Ok, well... after careful inspection of the new Smith and Wesson M&P 15, I am very impressed. I spent an hour cleaning all of the grime and shipping grease off of it, and now I am heading out to the range. I am bringing 200 rounds of M193 (5.56mm) ammo with me, to break it in. This rifle is fired alot at the factory, evidenced by the carbon on the back side of the firing pin head.

I have it set at mechanical zero, with the A3 type "carrying handle" and standard front sight tower. This is the basic M&P 15, and cost me $917.00 to my hands. That's shipping, tax and FDLE fee. It helps to have an FFL in the family... he he he.

Ok, off I go... pictures to follow. Gonna take some of the HH6 shooting. This is a great little rifle to start with. Sure, you can "build" one cheaper... but the fit and finish of this M4 is superior. It is VERY tight, and the trigger is one of the best "production" triggers I have felt. Definitely better than my issue Colt. That's for sure.

I look forward to adding on some parts to it to make it more unique... but, I can't fault it the way it is.

Stay tuned gang...
I looked at the RRA lower and upper and they are at right about the right price. Hopefully they will have them in stock when I get back in March.

GSXRanger- I am kinda curious of your opinions of your new S&W M&P 15. That looks like a decently priced M-4. Again, another one that isn't in stock right now. Hopefully they have something in stock that isn't highly overpriced when I get back.
Ok Gang... here's my hands on experience with my new Smith and Wesson M&P 15. I took the rifle out of the hard carrying case, which is pretty much a 30 dollar Dockosil single rifle case. Ho hum. The carbine was covered in grease and oil, and the bolt was sort of gritty feeling. The rifle came with a brand new, mil spec 30 round magazine, so I can add that to my eleventy six bazzillion mags I already have.

I took the rifle out in the shed, and gave it a very complete cleaning. This rifle has a 1 in 9 twist, Carbine length gas tube, lightened style barrel, with the traditional sight post up front. Nothing fancy... but the fit and finish were above supurb. The upper and lower mated with ZERO slop, and once cleaned, and properly lubed, the bolt operated silky smooth.

The handguards on the base model are the standard two piece M4 style, no rails. But, the carrying handle has the A3 style sight rail, and comes off easily. Standard Picatinny rails on the upper receiver.

The trigger, as I stated... is incredibly smooth for this price range. I put my Lymann guage on it, and it broke consistently at five pounds... give or take a few ounces either side. There is little to no creep on it, when dry firing it.

Off to the range we went.

The only ammo I had to break her in, was 1974 era, M-193 ball... which was made by Winchester, back in November of 1974. I have five hundred rounds of it still in white boxes... so, I figured I would run about 200 through it, just to break in the barrel, and see how it shot with 55 grain ball.

Here is the picture of the Range on Tamiami Trail in Miami. It's a really crappy range, the only distance you can shoot is out to 100 yards. They are very anal about their rules, one round every five seconds, etc... due to the high volume of fucksticks that frequent.


Here is the rifle, on the bench. Notice the light coat of oil... he he he

Ok, I started off shooting from a crappy rest, at 50m just to see if I could print on the 6 inch Shoot and See. I put the sights at mechanical zero, and had to move a total of 14 clicks right... which is almost spot on, for my issued Colt M4 from mechanical zero.

That got my windage right, after the adjustment. I still had some elevation issues... but, I was shooting at 50m, and could not use a standard M4 zero target.

Here I am shooting the rifle...


Here is the 50m target. Notice group 1, is off to the left. Not too shabby for the first 3 rounds out of the gun.

Groups two and three were fired successively. I have a 60x spotting scope that I noted the position of the impact of the rounds.

After sight adjustments, I stacked group 4 on top of each other.

I then moved the target out to 100m... and just used a fresh Shoot and See, 6 inch circle. With Iron sights, I was making a "lollypop" with the black shoot and see. I would rest the black circle directly on top of the sight post, and press the trigger. I was able to keep every single one of my rounds, within the shoot and see, iron sights with zero issues.

This is with very shitty ammo, and I can almost bet that with 62 grain ball, and an EOTech... this thing will shoot MORE than tight enough for a combat rifle.

I ran 200 rounds through it, cleaning the bore every 40. Not a single hiccup, or misfire, zilch.

My opinion of this rifle so far?


That is all.
Just remember that LMT, Colt, and RRA are 7075TI aluminum lowers and uppers while others are a lesser 6061 aluminum. To me it makes a big difference in quality and reliability of your weapon system.

Just something to think about.

BushMasters are 7075 T6 aluminum. So what is the difference between the TI and the T6? What do those designations mean?