A little over a year ago I bought and tested the Sig Sauer M400 SRP Carbine
The M400 SRP is exactly as shown in the image. I decided that it was time to make a few enhancements on an already awesome weapon. I did not, however
follow the list of goodies I have linked in that thread. I decided to go a different route instead.
I decided to work from the inside out on this one. I started with the stock bolt. My original idea was to replace it with a Low Mass bolt and carrier
assembly which would have cost me 250 bucks. However I quickly realized that I didn't need such an upgrade as low mass bolts are for saving ounces on
a weapon that is already light. And the upgrades I was going to make down the line were going to lighten this weapon up by a lot anyway. I left the
bolt and carrier assembly alone save for 2 springs: The extractor spring and the ejector spring.
Those of you who shoot AR 15s know that they can heat up. You also know that when you heat up steel(music wire springs) after a while they will
deform, they will lose their tension, and can even work-harden until they break. I decided to look for some more heat resistant, shape retaining
springs in the form of Chrome Silicon
alloy springs by Tubb Precision. I
also decided to purchase their flat wire version of the buffer spring, also a CS alloy spring. While heat resistance in the buffer spring isn't really
that paramount, shape retention and longer shooting cycle life is.
My next enhancement was the trigger. I was going to shell the 350 bucks for a 1.5 lbs Jard trigger assembly. However, I not only would have had to buy
a low mass bolt and a superlight titanium firing pin, I would have to spend the money every weekend I went shooting on ammunition with very soft
primers...I want a weapon that can shoot any kind of ammo. So I went with a 3.5 lbs. CMC Single Stage
Tactical Trigger with a flat trigger blade
. It is a remarkably smooth trigger and at 3.5 pounds there is NO travel time as you can see from the
linked YouTube video(Not made by me). That means very little movement and more accurate shots. I spend 174 bucks on it and it was well worth it.
I then moved outward and focused on the furniture. While I am a long time user and lover of Magpul products I did not use Magpul MOE for the entire
build. Instead I used the BMS Battlelink Minimalist
from Mission First Tactical. It is a solid stock for its shape and extremely light. Made for both Commercial and Mil-Spec buffer tubes..Be
sure you know which one you have!
I did use a lot of Magpul products in this build, however. Let me start with the handguards.
The Magpul MOE handguards
are built to take advantage of the modularity and "Barbiedoll"
aesthetics of the AR platform. Which means you can easily add control accessories, lights, optics, and lasers. They are also lighter than stock
handguards and they do not use over molded plastic materials. They are injection molded and extremely heat tolerant.
For added weapon control(the only gun control
you need) I purchased the Magpul AFG
Foregrip. Having used vertical foregrips on many weapons I just don't get proper ergonomic control of my weapon. I had previously been exposed to the
AFG on a friends AR and I loved it so on my weapon it went.
Then it was time to take advantage of the quick disconnect points built in to the lower receiver. For that I bought the
Magpul MS3 Multi-Mission sling
. Fully adjustable, it does not come with a built in QD swivel but
there are places that sell them with the QD swivel adapter attached. The position of the QD socket and the design of the sling make it easy to rest
the weapon by your side, or have it at the ready immediately. This is important, I believe, in a defensive weapon - which is the intent of the weapon
as originally bought, and it is the state of mind being kept in making these enhancements.
It was then time to move on to sights. Here again I went with Magpul products for my flip up back up sights. Since the M400 SRP is a flat top railed
weapon it does not have a rear or front sight. So I decided that I would purchase the Magpul MBUS
back up sight system. Like
most Magpul products they are made of high strength injection molded polymer material. They are fully adjustable and can be used to a high degree of
accuracy by those of us who are used to using iron sights...But this brings me to my next enhancement...
The EOTech 512
. This holographic battle sight has been field proven. With over 1000 hours of
continuous use on 2 lithium-ion aa batteries, proven rugged construction, and accuracy, it was an obvious choice for my defensive weapon. It features
a 65 MOA circle around a 1 MOA dot. This means that it can be calibrated easily for both close quarters and ranged(1-300 meters) combat. With the
exception of the far more expensive(and frankly better) Trijicon ACOG reflex sight...No other sight system can come close to what EOTech has created
in its line of products.
I then needed something for low light, or simply dark room use. I was looking for something lightweight and energy efficient and I found just that
when I came across the Torch low profile backup light from Mission
and manufactured by Princeton Tec. This is possibly the lightest weapon light on the market and it is run by a single watch
battery. I mounted it next to the AFG, I can easily activate it with my thumb, and it gives me a 12 hour burn time at 20 lumens. More than enough for
There was one last thing...If you look at the flash hider on the stock SRP it just doesn't look like it would belong on a weapon that was so
personalized. I don't like compensators because of the localized noise they produce. Compensators are for target shooting anyway and this is a
defensive weapon. I needed to find something that fit the mold of a defensive weapon AND looked good on the end of my rifle. I decided to purchase the
Yankee Hill Machine Annihilator Flash Hider
flash hider not only looks good, but it send a message and functions as advertized. You also do not have to time it for installation. You simply
removed the old flash hider and crush washer, install the new washer, and grab a wrench and torque the Annihilator down until it won't turn anymore
and you're good to go.
After taking an already reliable stock weapon and adding internal and external enhancements for accuracy, control, form, and function I feel confident
that I have created one of the best AR platform weapons I will ever use.
edit on pSat, 09 May 2015 13:25:01 -050020159America/Chicago2015-05-09T13:25:01-05:0031vx5 by projectvxn because: (no reason