Shortened BCM build



My objective with this carbine build was to make something suitable for close quarters with full night vision capability. While this build is still evolving with its various optics, lights and laser systems… how it’s setup right now achieves my objective.



The stock I selected for this was the B5 Systems SOPMOD. It’s a good collapsing stock and I’ve been very happy with it. But like many stocks… it’s a stock. You put it in your shoulder to help control recoil. I run this one two clicks out. So I’m fairly compressed on my weapon.



The lower used was an inexpensive LRB. The LPK (lower parts kit) was a simple CCMG. Regular safety. Regular mag release (although I now have a Magpul BAD lever on it). But the trigger… this is a major improvement over a standard milspec trigger that comes with most LPKs.

I’m running the Geissele SD3G (Super Dynamic Three Gun) with the 4lb spring. It’s amazing. I can crank off 7 rounds in under a second controllably. It’s a smooth crisp break with an excellent reset. The reset is aided by a powerful spring so you don’t have to push your finger off the trigger to get the reset like you have to do on some competition triggers. You just let go a tiny bit, and the trigger springs forward to reset. And then you’re set to go. It’s an excellent trigger.



The upper assembly was purchased as a complete build from Bravo Company Manufacturing. It’s a 16″ chrome-lined mid-length gas system barrel. With a 12″ Midwest Industries Keymod rail. Bolt is obviously from BCM, and the charging handle is their mod 2. The BCM charging handles are fantastic. Unlike a milspec charging handle, the BCM charging handle doesn’t make it feel like you’re pulling the entire weapon system to the left. It’s just a straight smooth pull to the rear.

Now, while this upper started as a 16″, the barrel was sent off to a company to be chopped shorter to make the rifle even more controllable. The company who did my barrel chop isn’t doing them anymore, and as of right now I don’t have anyone to recommend.



As you guys know, the legal length of a rifle is 16″. So chopping a barrel below 16″ will turn the rifle into a pistol or SBR class weapon system. I wanted to remain “rifle legal” so I had the unnamed company pin and weld a Griffin Armament Taper Flash hider to the barrel. This is a pretty permanent solution, but it puts my barrel + flash hider right at 16.1″. Versus: If I had kept my barrel 16” and then added the 2.6″ Griffin device on. That would put the total rifle length at 18.6″. So I effectively eliminated 2.5″ off my overall rifle length. Pretty cool huh?

You are probably asking, what does that do for ballistics? Well, for every inch removed you lose a tiny bit of feet-per-second velocity. A 13.7-14.5 barrel will perform a little differently out to 200-400 yard ranges than a regular 16-18″ barrel. But if the rifle build is intended for 200 (even 300) yards and in, it will be fine.

Saving that 2.5″ inches makes a HUGE difference in maneuverability. It also eliminates some weight, and keeps the weight of the muzzle device closer to the support hand. Which helps with target transitioning times. This rifle system is short enough to fit in my 5.11 Covert rifle bag without taking the rifle apart. Pretty cool.

I chose the Griffin Armament Flash Hider for a few reasons… I run this rifle with night vision so I didn’t want a muzzle brake/compensator because they cause unwanted flash. The Taper is a cool mount because it has threads for Griffin’s suppressors. One of which will be added to this rifle in the near future. While this rifle doesn’t have a muzzle brake to aid in recoil management, it hasn’t been a big problem for me.




The back-up rear sight is a Magpul Pro. The front sight, on the other hand, is part of the Unity Tactical VTAC Fusion hub. More on that later.

I chose a red dot for this build because this is a CQB rifle. Not a DMR or competition gun. It’s intended purpose is home defense and running and gunning within 200 yards. Primarily. The red dot of choice was an Aimpoint T1. In the 2 MOA configuration. The mount is an American Defense Manufacturing lower 1/3 co-witness QD mount. I like running QD mounts since I’m experimenting with optics and other gear all the time. Having the ability to pop an optic off to quickly add a different one to play with is very important to me. But isn’t necessary for most folks.

I choose small MOA red dot optics because the smaller the MOA the more margin for error you have once you start engaging at further distances. If you want the dot “larger” for faster acquisition, the dot can simply be turned brighter.



I’m running a Ferro Concepts Slingster most of the time with this build. I have a Midwest Industries QD adapter which runs on the rail, and then a Magpul ASAP plate where the stock meets the upper assembly. This is my favorite sling setup. It’s very easy to manipulate the weapon without the sling getting in the way.



Alright. This is the most complicated part of this build, because I like my lasers/lights to be easily accessible. And ambidextrous if possible. I also like running my lights and lasers momentarily. And on top of all that… I like getting my arm as far out on the rail as possible for maximum control. The problem: lights and lasers take up precious real estate and it can be difficult to setup them up for easy ambidextrous use (if I transition shoulders).

So… in order to run electronics easily with either hand, I put buttons right at 12 o’clock. I used the Surefire dual pressure pad. This pad connects to both my Surefire Scout (500 lumens) and my ATPIAL-C together. The front switch activates the light momentarily. The back switch activates the ATPIAL. I then specify on my ATPIAL whether I want a red laser, IR laser, or IR laser + illuminator.


Having my IR laser and light further out creates a problem though – my arm has to retreat closer to the magwell which I don’t like a whole lot. But it’s necessary if I want to run both systems ambidextrously. If I put the laser in the back near my optic, my thumb can cover the IR laser/illuminator while I’m working the pressure pad. So it has to be in front.


There are many pros and cons to this setup. But as of right now, this is the only way I’ve figured out how to easily activate an IR laser and weapon light with either hand. I’m utilizing the Unity Tactical Fusion system to consolidate real-estate.

I run a BCM KAG grip as a reference point, and as a vertical object for me to pull back on to aid in recoil control and target transitioning. Vertical and angle grips all come down to your personal preferences. I don’t believe there is one type that is THE BEST. It all comes down to your body mechanics and what is comfortable for you. But it is proven that the more hand on the rail/bore, the better.



I get asked all the time what I used to spray paint this rifle. I used three different colors of Rustoleum. Their camo series. The first layer was an avocado color that I wasn’t happy with at all. Then I tried their tan. Too bright. Then I went with their dark green and it was perfect. Over time, the three layers have deteriorated, but they deteriorate in layers and you can see the layers underneath. It’s actually a super cool effect. Do I care that the paint is coming off? No way. This is a tool. Not a show piece.

I spray paint my rifles to break up their outline. An all-black gun is a target indicator. It’s high contrast. It sticks out. An ab-normally colored gun has many advantages. Unless it’s bright orange or white, obviously.


COST BREAK DOWN (retail pricing… and rough)

LRB lower + LPK $200
Sopmod stock $58
Geissele SD3G $280
BCM Grip $20
BAD lever $25

BCM upper (with rail) $750
Griffin Armament Taper flash hider $100
Barrel chop job $150
BCM rail panels $20
Ferro Concepts Slingster $45

Aimpoint T1 $580
ADM mount $80
Magpul Pro BUIS $88

VTAC Fusion Hub $220
Surefire Scout $230
Surefire dual pressure pad $108
ATPIAL-C $1400

TOTAL: $4374.00

Thanks for reading. – Lucas Botkin