txf15crewchief
11-16-13, 03:56
My goals with this carbine were very simple. Assemble a durable, reliable, lightweight carbine with quality yet affordable parts. The uses would be as an alternate home defense in a suburban environment, but also usage out to 200 yards or so. Sounds simple enough, but I learned very early on that not every part can be trusted over the nearly year it took to finish this project. Also I apologize now for the long post.
Lower:
The lower is a Palmetto State Armory and originally was ordered with a complete Magpul "Premium" PSA lower parts kit and receiver extension kit. After lubrication and installation of the fire control group I noticed how awful the trigger was even by mil-spec trigger standards. I removed and re-lubricated the components and after dry fire and range time, it seemingly grew worse. After removal yet again and closer inspection, on the face of the trigger at the engagement surface, an entire corner was lopsided and had a relatively rough surface. First PSA component trashed, and replaced by an ALG QMS. No problems since, with a crisper, lighter pull than than that of the previous unit.
Second was the receiver extension. I will preface this by saying that I did not originally stake it, and not surprisingly the RE rotated on one less than one magazine. Murphy strikes quickly. When it did rotate, the "tooth" of the endplate gouged the threads. Well upon removal and replacement by a Daniel Defense 7075-T6 RE, I made several observations, such as the threads of the DD tube were deeper than those of the PSA, while the "slot" for the endplate "tooth" was longer on the DD as well. The PSA seemed to be missing a dry film coating on the interior and had various dimensional differences from the DD including the "lip" that retains the buffer detent and spring in place being smaller on the PSA and the B5 Bravo becoming a significantly snugger fit after the change to the DD. Even the drain hole was a different size between the two, with the PSA being the larger of the two. With the way PSA has been, I would not be too terrible surprised if my supposedly "7075-T6" RE was actually constructed of 6061-T6. If anyone can tell the difference from the photos, I would be glad to learn. The ungouged RE is the DD, the PSA, the trashed one. Yes, I immediately staked the new one on ;)
http://i173.photobucket.com/albums/w67/icyaquarius86/IMAG2379_zpsfc057378.jpg (http://s173.photobucket.com/user/icyaquarius86/media/IMAG2379_zpsfc057378.jpg.html)
http://i173.photobucket.com/albums/w67/icyaquarius86/IMAG2380_zpsfe5c5af8.jpg (http://s173.photobucket.com/user/icyaquarius86/media/IMAG2380_zpsfe5c5af8.jpg.html)
http://i173.photobucket.com/albums/w67/icyaquarius86/IMAG2381_zps41a482af.jpg (http://s173.photobucket.com/user/icyaquarius86/media/IMAG2381_zps41a482af.jpg.html)
Even the PSA buffer spring was of a lower resistance strength in comparison to an equally new BCM spring. While I'm not certain whether or not it matters but the PSA spring was a metallic, soft grey color while the "mil-spec" BCM is a golden brown hue. Not sure if that is the coating or a composition difference. Again, I would be glad to learn the difference.
As someone with rather large hands (I'm 6'6" tall), I like the size of the MOE grip, but prefer the angle of the Gunfighter Grip. At the time this build was started during the panic, the Mod 1 was my only option, thankfully BCM has seen fit to produce a grip (GFG Mod 3) for us overly large Americans. That extra meat on the grip allows me to have a proper distance to the trigger and not feel cramped.
Upper:
Luckily (or intelligently), I knew from the beginning I'd be using a BCM Lightweight Mid-length 16" barreled upper. I did not want to go through the hassle of pinning a muzzle device to a barrel, or having weight on the wrong end of the barrel. A standard A2 flash hider is more than good enough for my intended purposes and as I already suffer from 20% hearing loss courtesy of the USAF, I'd prefer to not lose what I have left. As my only plans for accessories called for a weapon mounted light, a Magpul MOE handguard with Picatinny mount was all that was required. Although I had a spare Gen 1 Gunfighter Charging Handle lying around, I decided to go with a Gen 2 and like that it is slightly refined and less prone to pinching my giant, E.T.-like fingers.
At the time I ordered this upper from Rainer, BCM BCGs were only sporadically in stock, yet the Centurion C4 was a relatively new arrival in the market. After quick research and learning that these were shot peened and MPI'ed, I was fine with them not being HPT'ed in order to prolong bolt life. Add Monty and Centurion's stellar reputation for quality it was a no brainer as was the choice of the Blue Force Gear VCAS.
Sights were about the only thing I grabbled with aside from the receiver extension issue. Although the Aimpoint Micro is the clear choice here and would satisfy 99% of my requirements for optics, I very nearly chose the Leupold VX-R Patrol 1.25-4X for having the 4X magnification. However the added weight, an actual low end magnification of 1.5X, cost and overall planned use meant in the end I chose a Aimpoint Micro R-1 from Grant and a ADM SOCOM height mount from the EE. I already had a rear Magpul MBUS so it went on without much fuss.
As far as the weapon light, normally I have used the Surefire X300 and would have yet again if not for the introduction of the Inforce WML and specifically the momentary-on only variant spec-ed by Haley Strategic Partners. 200 lumens is more than enough for my needs, and although I'm sure a 500 lumen X300 Ultra would be great for hog hunting, that's not the primary purpose of this carbine.
So after all that, here's the carbine in it's finished form, save a IWC MOE sling mount:
Close up of the Centurion C4 BCG, great staking, chromed carrier
http://i173.photobucket.com/albums/w67/icyaquarius86/IMAG2197_zps5293b76d.jpg (http://s173.photobucket.com/user/icyaquarius86/media/IMAG2197_zps5293b76d.jpg.html)
The complete carbine
http://i173.photobucket.com/albums/w67/icyaquarius86/IMAG2443_zpsff88d192.jpg (http://s173.photobucket.com/user/icyaquarius86/media/IMAG2443_zpsff88d192.jpg.html)
http://i173.photobucket.com/albums/w67/icyaquarius86/IMAG2442_zpsb8d54175.jpg (http://s173.photobucket.com/user/icyaquarius86/media/IMAG2442_zpsb8d54175.jpg.html)
http://i173.photobucket.com/albums/w67/icyaquarius86/IMAG2441_zps60d9c419.jpg (http://s173.photobucket.com/user/icyaquarius86/media/IMAG2441_zps60d9c419.jpg.html)
Centurion C4 Bolt Bolt Carrier Group
BCM 16" Lightweight Mid
BCM Gunfighter Mod 4 Charging Handle
BCM Gunfighter Mod 3 Grip
BCM Mil-spec Carbine Action Spring
Rainer Arms H-buffer
B5 Systems SOPMOD Bravo
Daniel Defense Mil-spec 7075-T6 Receiver Extension
ALG Defense Quality Mil-Spec Trigger
PSA Lower Receiver
PSA Lower Parts Kit
Magpul MOE Trigger Guard
Magpul MOE Mid-length FDE handguard
Magpul Cantilever Picatinny rail section
Inforce/HSP 200 lumen WML
Aimpoint Micro R-1
Tango Down IO Cover
Blue Force Gear Vickers Combat Applications Sling
If I had to do it over again, I didn't have the lower receiver, I would've just bought nearly the identical configuration from Grant and been done with it. Maybe even that LW Mid with the Geissele Mk4 SMR...
Lower:
The lower is a Palmetto State Armory and originally was ordered with a complete Magpul "Premium" PSA lower parts kit and receiver extension kit. After lubrication and installation of the fire control group I noticed how awful the trigger was even by mil-spec trigger standards. I removed and re-lubricated the components and after dry fire and range time, it seemingly grew worse. After removal yet again and closer inspection, on the face of the trigger at the engagement surface, an entire corner was lopsided and had a relatively rough surface. First PSA component trashed, and replaced by an ALG QMS. No problems since, with a crisper, lighter pull than than that of the previous unit.
Second was the receiver extension. I will preface this by saying that I did not originally stake it, and not surprisingly the RE rotated on one less than one magazine. Murphy strikes quickly. When it did rotate, the "tooth" of the endplate gouged the threads. Well upon removal and replacement by a Daniel Defense 7075-T6 RE, I made several observations, such as the threads of the DD tube were deeper than those of the PSA, while the "slot" for the endplate "tooth" was longer on the DD as well. The PSA seemed to be missing a dry film coating on the interior and had various dimensional differences from the DD including the "lip" that retains the buffer detent and spring in place being smaller on the PSA and the B5 Bravo becoming a significantly snugger fit after the change to the DD. Even the drain hole was a different size between the two, with the PSA being the larger of the two. With the way PSA has been, I would not be too terrible surprised if my supposedly "7075-T6" RE was actually constructed of 6061-T6. If anyone can tell the difference from the photos, I would be glad to learn. The ungouged RE is the DD, the PSA, the trashed one. Yes, I immediately staked the new one on ;)
http://i173.photobucket.com/albums/w67/icyaquarius86/IMAG2379_zpsfc057378.jpg (http://s173.photobucket.com/user/icyaquarius86/media/IMAG2379_zpsfc057378.jpg.html)
http://i173.photobucket.com/albums/w67/icyaquarius86/IMAG2380_zpsfe5c5af8.jpg (http://s173.photobucket.com/user/icyaquarius86/media/IMAG2380_zpsfe5c5af8.jpg.html)
http://i173.photobucket.com/albums/w67/icyaquarius86/IMAG2381_zps41a482af.jpg (http://s173.photobucket.com/user/icyaquarius86/media/IMAG2381_zps41a482af.jpg.html)
Even the PSA buffer spring was of a lower resistance strength in comparison to an equally new BCM spring. While I'm not certain whether or not it matters but the PSA spring was a metallic, soft grey color while the "mil-spec" BCM is a golden brown hue. Not sure if that is the coating or a composition difference. Again, I would be glad to learn the difference.
As someone with rather large hands (I'm 6'6" tall), I like the size of the MOE grip, but prefer the angle of the Gunfighter Grip. At the time this build was started during the panic, the Mod 1 was my only option, thankfully BCM has seen fit to produce a grip (GFG Mod 3) for us overly large Americans. That extra meat on the grip allows me to have a proper distance to the trigger and not feel cramped.
Upper:
Luckily (or intelligently), I knew from the beginning I'd be using a BCM Lightweight Mid-length 16" barreled upper. I did not want to go through the hassle of pinning a muzzle device to a barrel, or having weight on the wrong end of the barrel. A standard A2 flash hider is more than good enough for my intended purposes and as I already suffer from 20% hearing loss courtesy of the USAF, I'd prefer to not lose what I have left. As my only plans for accessories called for a weapon mounted light, a Magpul MOE handguard with Picatinny mount was all that was required. Although I had a spare Gen 1 Gunfighter Charging Handle lying around, I decided to go with a Gen 2 and like that it is slightly refined and less prone to pinching my giant, E.T.-like fingers.
At the time I ordered this upper from Rainer, BCM BCGs were only sporadically in stock, yet the Centurion C4 was a relatively new arrival in the market. After quick research and learning that these were shot peened and MPI'ed, I was fine with them not being HPT'ed in order to prolong bolt life. Add Monty and Centurion's stellar reputation for quality it was a no brainer as was the choice of the Blue Force Gear VCAS.
Sights were about the only thing I grabbled with aside from the receiver extension issue. Although the Aimpoint Micro is the clear choice here and would satisfy 99% of my requirements for optics, I very nearly chose the Leupold VX-R Patrol 1.25-4X for having the 4X magnification. However the added weight, an actual low end magnification of 1.5X, cost and overall planned use meant in the end I chose a Aimpoint Micro R-1 from Grant and a ADM SOCOM height mount from the EE. I already had a rear Magpul MBUS so it went on without much fuss.
As far as the weapon light, normally I have used the Surefire X300 and would have yet again if not for the introduction of the Inforce WML and specifically the momentary-on only variant spec-ed by Haley Strategic Partners. 200 lumens is more than enough for my needs, and although I'm sure a 500 lumen X300 Ultra would be great for hog hunting, that's not the primary purpose of this carbine.
So after all that, here's the carbine in it's finished form, save a IWC MOE sling mount:
Close up of the Centurion C4 BCG, great staking, chromed carrier
http://i173.photobucket.com/albums/w67/icyaquarius86/IMAG2197_zps5293b76d.jpg (http://s173.photobucket.com/user/icyaquarius86/media/IMAG2197_zps5293b76d.jpg.html)
The complete carbine
http://i173.photobucket.com/albums/w67/icyaquarius86/IMAG2443_zpsff88d192.jpg (http://s173.photobucket.com/user/icyaquarius86/media/IMAG2443_zpsff88d192.jpg.html)
http://i173.photobucket.com/albums/w67/icyaquarius86/IMAG2442_zpsb8d54175.jpg (http://s173.photobucket.com/user/icyaquarius86/media/IMAG2442_zpsb8d54175.jpg.html)
http://i173.photobucket.com/albums/w67/icyaquarius86/IMAG2441_zps60d9c419.jpg (http://s173.photobucket.com/user/icyaquarius86/media/IMAG2441_zps60d9c419.jpg.html)
Centurion C4 Bolt Bolt Carrier Group
BCM 16" Lightweight Mid
BCM Gunfighter Mod 4 Charging Handle
BCM Gunfighter Mod 3 Grip
BCM Mil-spec Carbine Action Spring
Rainer Arms H-buffer
B5 Systems SOPMOD Bravo
Daniel Defense Mil-spec 7075-T6 Receiver Extension
ALG Defense Quality Mil-Spec Trigger
PSA Lower Receiver
PSA Lower Parts Kit
Magpul MOE Trigger Guard
Magpul MOE Mid-length FDE handguard
Magpul Cantilever Picatinny rail section
Inforce/HSP 200 lumen WML
Aimpoint Micro R-1
Tango Down IO Cover
Blue Force Gear Vickers Combat Applications Sling
If I had to do it over again, I didn't have the lower receiver, I would've just bought nearly the identical configuration from Grant and been done with it. Maybe even that LW Mid with the Geissele Mk4 SMR...