Project ARMOR 5.56: The AR MOuntain Rifle
This is the first configuration of three “Mountain” ARs: Project ARMOR 5.56 is a small game hunting (coyotes and such) and part-time precision AR while Project ARMOR 6.8 will be similarly prepared for medium game in 6.8. The last, the ARDVARK (AR Designated VARmint Killer) is a variation in .204 Ruger for hunting small varmints like prairie dogs.
Primary Goals and Background:
The primary purpose of this rifle is hunting small game to 300y with a secondary purpose of precision work shooting paper and steel out to approximately 500y. There was no immediate plan to make this a self-defense type of firearm.
To achieve this I needed to incorporate:
- Attributes of a mountain rifle
- Precision
- Portability
For precision, I wanted at or sub-MOA setup and an optic that would allow for precision shooting. Portability required a 16” barrel and a collapsible stock so I could easily fit in a backpack for extended hikes & hunts. The final criterion, a mountain rifle, required the combination of the portability in a lightweight package with an appropriate optic. My definition of lightweight for this project was at least a 2 lb reduction in weight compared to my old SPR: 7.7 lbs. with a scope. I decided to shoot for 7.5 lbs. with the optic.
The budget for this rifle, with accessories was $5,000. Naturally, I tried to spend as little as possible!
Parts Selection
Doing a little more research I sought to draft a short list of appropriate optics and barrels first and, using a spreadsheet depicting weights for each component of the rifle, refine my choices based on my overall weight criterion. Some optics were simply too heavy to meet my goals, e.g., the IOR 2-12x32 or USO 1.8-10x37 are probably perfect midrange optics for this application, but both are portly at 28 oz. and had to be eliminated from the list. The S&B Short Dot is a fantastic optic, but too heavy and over my budget for this one. I really wanted the discontinued NF 2.5x10x24, but these are very difficult to find and I really wasn’t keen on trying to find a pristine pre-owned optic sight unseen. I settled on the NF 2.5-10x32 with NPR-2 reticle and ZS MOA turrets. It meets most of my criteria except it’s a bit heavy at 19 oz. (2 oz heavier than the x24), so I decided to become a little more creative at trimming weight from other parts to achieve the 7.5 lb. goal.
The barrel selection was based on four criteria
- Caliber
- Weight
- Precision capabilities
- Ability to use a wide variety of ammo
Thus, I selected the SS lightweight profile 16” Noveske. At 28.2 oz. (without the GB) and likely very precise, I reasoned that this was a good choice.
The rest of the parts (and rationale):
Upper Receiver
- Noveske lightweight SS BBL & GB (I had Marvin Pitts dimple the front end to help with balance and remove an additional 1.5 ounces).
- PWS TTO compensator (Lightweight at 46 g and very functional. Useful for quick follow-up shots. I did not have a flash suppression requirement.)
- VLTOR MUR-1S Upper (Lighter than the MUR-1A and probably overkill for my application. I did not need FA for this rifle. Was quite surprised to find that this forged upper is nearly the same weight as a standard flattop upper: 0.4 ounces heavier).
- KAX URX-3 (This may not appear to be the lightest rail, but I felt that I might want BUIS on this rifle at some point, needed a sling mount and the ability to attach a bipod. When you add the weight of rails and a front sight to, say an 11” TRX Extreme rail, the URX-3 weighs the same or lighter. I further modified the lower portion of this rail by removing the partial-length heat shield, slightly enlarged the vent holes and removed the threaded center tabs that are necessary for mount accessory rails. This decreased the weight from 13.6 to 12.0 oz and that includes the barrel nut.)
Modified URX-3 compared to unmodified.- BCM GF CH, medium (only a couple of grams heavier than a standard CH and a lot easier to manipulate. Originally I used the large latch, but found that the tiny bit of extra length kept hanging up in my backpack.)
- JP low mass BC (Very light carrier that is a bit finicky with respect to cyclic rate. Based on another project (and credit to Robb Jensen), I think I’ve tuned this to my liking with the A5 buffer and rifle spring. The carrier is 2.9 oz lighter than std M16.)
- Noveske bolt (Perfect for my needs)
- BCM FP, cam pin, retaining pin
Lower Receiver:
- Noveske lower
- G&R LPK (top notch quality with Grant’s hand selected components)
- Magpul trigger guard
- Geissele SSA-E trigger (Using this for precision and this is likely a part that may require a lot of field time for evaluation as I’m not sure how it will work hunting)
- Magpul MOE basic grip (lightweight and comfortable. I use these on all but one of my ARs)
- Novekse QD receiver end plate (May find the additional QD location useful)
- Colt castle nut
- VLTOR IMOD clubfoot stock (Wanted a collapsible stock with good cheek weld. This is one of the lightest collapsible stocks and a substantial weight savings compared to other similar stocks including the EMOD. Without the storage pods and butt pad, the IMOD weighs only 5.4 oz and with one cheek/storage pod it weighs 6.8 oz. FWIW, the older MODSTOCK is even lighter but I understand the IMOD to be a little more robust.)
- VLTOR A5SR receiver extension (I selected the A5 due to the lightweight bolt carrier choice and the need for the A5 buffer and rifle spring to optimize cycling. The A5SR has one less notch compared to the standard A5 which was necessary with the IMOD so the RE doesn’t stick out the back when fully collapsed.)
- VLTOR A5 Mod 2 buffer (This is a standard weight A5 buffer with all of the tungsten weights replaced with steel. It weighs 3.7 oz.)
- Brownells chrome silicon rifle spring (Selected per above and the BC choice)
Optics and Accessories
- NightForce 2.5-10x32 with NP R2 reticle and ZS MOA turrets (This reticle was selected based on my goals and is appropriate for holdovers when hunting. I selected the ZS feature as based on lots of user-feedback.)
- Nightforce Unimount 30 mm X-High (I didn’t need a QD mount and this is 1.7 oz lighter than the LaRue at 5.4 oz. I think this is the lightest, quality one-piece mount made. I tried lightweight rings, but the NF’s eye relief rendered this impractical).
Now we know what these actually weigh
- Atlas Bipod with LaRue LT-171 lever mount (Very sturdy. Used for bench work. Heavier than a std Harris and will not use for hunting)
- SnipePod V2 24” bipod (For hunting only. Five ounces! May purchase their 10” bipod to take along too. The 10” model only weighs 2 ounces)
- BFG/Vickers 2 PT padded sling w/QDs (Use these on other ARs and am familiar with them. I need more field time to better evaluate. I may try the Tactical Intervention military rifle sling I use on my Remy 700.)
- PMAGs- 20 round cap (Light and reliable)
Assembly
Since the barrel was going to be sent to Marvin Pitts for dimpling, I decided to include the KAC HG and upper for installation as I was not keen on buying a $250 KAC barrel nut wrench. Additionally, the KAC HG does not fit flush with my upper receiver and must be milled to do so. Marvin was more than capable and happy to complete the work. I was very satisfied with the outcome.
Marvin does amazing work!
The rest of the rifle went together without a hitch.
Yes, I staked the endplate
SummaryI came in under budget and underweight. Total for the build was approx. $3,727 for the rifle and optics and $4,300-ish with all of the accessories. The rifle weighs exactly 5.97 pounds without optics and 7.5 with the NF scope and mount.
Range report and function testing soon!
The ARMOR 6.8
Project ARMOR 6.8 will be setup in a similar fashion without the stringent weight or (semi) tactical precision requirement. As it is configured for potential use in a tactical role, I’ll be using BUIS, a QD optic mount and a functioning FWD assist.
My goal for this rifle is 7.75lb with a flexible hunting optic in 3-9x power. I also want a decent reticle for low-light hunting. More on this one later.
6.8 Upper to go to Marvin for dimpling and assembly
Reply With Quote
Originally Posted by TRIDENT82
Bookmarks