I want this gun to be something of a hard working tool, and not so much a "gamer's toy" that might be more finicky in terms of reliability. As such, I decided to go with a full power recoil spring. Further reading suggests that flat wire springs might be a better alternative to conventional round wire springs.
Strike Industries claims increased forward bolt load and reduced compression force, along with higher spring life compared to its MilSpec counterpart. What this means is that it closes the bolt with more force while being easier to cycle the action. This is made possible because of the flat wire design, allowing for the spring to be physically longer which means spring strength can be adjusted. Either way, the longer spring life and reduced "twang" is what sold me.
As for the cam, it turns out that some piston AR's suffer from something called receiver gouge. This issue is common enough in piston AR's that POF decided to make a special cam pin that helps to reduce the chance of developing receiver gouge.
The top of the cam pin is basically a roller bearing instead of a flat piece of metal. This means that if the cam pin were to contact the upper receiver, the bearing would, in theory, roll along the receiver while a standard cam pin might scrape and dig into the receiver. Looking at pictures of rifles with receiver gouge was enough to make me order this part. At the time I ordered this, most everyone was out of stock. I was impatient and ordered it, and now you can find better deals all over the place. Learn from my mistakes, you don't need to order non-critical parts until you absolutely have to. Even if I completed the rifle, I could have run the regular cam until I got a better deal on this.
As my build list now stands:
Granite Ridge Outfitters
Primary Arms
Estimated Grand Total: $1,856.98
- Criterion 16" Hybrid CL Barrel - $258.84
- MAGPUL M-LOK AFG - $22.76
MAGPUL MOE K Grip- $15.04Seekins Precision Ambidextrous Safety Selector Kit- $29.18Mission First Tactical Battlelink Minimalist Stock- $45.08Strike Industries Enhanced Ultimate Dust Cover- $11.60Patriot Ordnance Factory Anti-Tilt MilSpec Buffer Tube- $41.16- Superlative Arms Adjustable Piston System - $248.55
Bravo Company Gunfighter Charging Handle MOD 5 - Small- $47.57CMMG Gunbuilder's Lower Parts Kit- $45.40DPMS Firing Pin Retaining Pin- $1.56DPMS Firing Pin- $6.91DPMS Castle Nut- $2.86D.S. Arms Carbine Buffer- $9.42- Vortex Spitfire Prism Scope - $249.99
TAPCO Gen II AR Stock Wrench- $9.45- MAGPUL BEV Block - $44.48
Chamber Flag- $2.50
Elftmann Tactical 3-Gun Trigger- $243.00
POF AR-15 Roller Cam (.223/5.56)- $27.37
Primary Arms
Receiver End Plate- $4.00
NP3 Plus Relia-Bolt- $60.79
VG6 Epsilon Muzzle Brake- $62.00
Total cost to date: $1032.36
Estimated cost remaining: $824.62
Estimated Grand Total: $1,856.98
The cost of the roller cam brought the total up again, but I'm still under $2000 total including tools. More updates to come!
'Till next time.
-AA