Ok...I don't really do this very often, but out of the projects I have tackled, this one seems to be the most rewarding so I thought I would share.
I have been searching for a suppressor host for my YHM phantom 30 cal can and have sampled a couple rifles. I owned a M1A socom and a cheaper FAL recently. Neither of these really rang my bell. I really didn't want to spend the cash on a high end 308AR, but bit the bullet and did it a little at a time. My goal was to build a sub moa battle rifle.
I ordered a Mega Machine monolithic uppper and ambi lower combination and all I can say is wow. This stuff is the nicest kit I have had the pleasure to get my skinners on. Fit and finish is second to none. Finish seems to be hard as hell and all corners are nicely rounded with machining transitions almost undetectable. Most of the roll pins have been replaced with threaded allens. Additionally, there is a upper/lower tensioning screw so you can fine tune the fit. The upper/lower came with detent pins, an ambi bolt release system and dust cover assembly all factory installed. The kit also came with a proprietary barrel nut and wrench for installation. Installation instructions were well written and extremely clear. Barrel installation was a breeze just as any other AR platform. The supplied barrel wrench has a provision for a 1/2" torque wrench and the instructions call out the specific torque.
For the rest of the upper build I went with a 18.5" stainless match grade barrel from fulton armory as this was the best balance of cost/performance for my needs. The gas system is rifle length with a JP Rifles .936" adjustable gas block. Bolt is a JP enhanced 308 bolt riding in a DPMS chrome bolt carrier. The charging handle is a PRI gasbuster. Prior to ordering the barrel, I sent my bolt to Fulton Armory so they could install the barrel extension and achieve the proper headspace. I would highly recommend this to anyone building a 308 for safety reasons. Another caveat on the barrel is that the fulton armory barrel threading is just a bit too long (.030” to be exact) to accommodate the YHM quick detach suppressor flash hider. I have yet to remedy this, but my plan is to have the barrel shortened by .050” and re-crowned so the suppressor flash hider will seat on the barrel shoulder. Additionally, the upper will eventually wear an Atlas bipod, but it has been on backorder going on 3 weeks now.
For the lower, I installed a CMC trigger group again a great balance of performance/cost. I run one of these in my SBR AR. Nice, crisp break and very little overtravel. I went with a Magpul UBR stock initially but just couldn't get the cheek weld I wanted with a scope, so changed it out to a magpul PRS for the AR10. The lower also wears a Magpul MIAD grip and sports an ambi safety lever from AR15.com. Another interesting part I came across that I have been more than happy with is the JP rifles captured silent buffer spring. This is a completely contained spring/buffer combination specifically for the AR308 platform (they make one for AR15 as well). It is the correct length for carbine stocks but comes with a spacer to allow it to work with rifle length buffer tubes as well. I also installed a troy ambi mag release button to stay with the ambi theme.
For glass, I went with a Larue tactical PSR one piece quick detach mount with 20 moa built into the package and SWFA's new SS 12x42 fixed power MIL/MIL scope. The scope is another great piece for the price/performance ratio. Glass is super bright and clear in low light, reticle has been well thought out and reticle subtensions/turret adjustements are both in MILs.
First impression when you pick up the rifle is that it is pretty heavy. I haven't had it on a scale yet, so exact weight is unknown.
Range report on this sukka is what one would expect from a top notch rifle in 308. First of all let me preface this with the statement that I am no expert shooter and have very little experience with precision shooting. I shot a combination of Remington match grade 168gr, Federal match grade 168gr and Federal Fusion 150gr on my first range trip. I dialed in the scope and did a little barrel break in with the first 20 rounds. I sent a couple wet patches followed by a dry patch down the bore every round for the first ten and every three rounds for the next 9. I then shot a few 5 round groups. It was hot that day (in the 90's) with a little bit of wind (prolly 10mph cross wind) and all groups were shot from a bench on bags at 100 yards. Also want to note that these were shot un-suppressed as I just received my suppressor and haven't had a chance to shoot it yet .
All three types of ammo were shot in 5rnd groups with the Federal Match grade 168 gr holding the tightest group at .610". The Federal Fusion and Remington match grouped at .910" and .795" respectively. I am sure the rifle can do better as my eyes are old and I am not the steadiest person behind a rifle even on bags and a bench. Needless to say, I am extremely happy with the performance that was demonstrated. Next thing will be to work up a handload to see if I can improve on the group I shot with the Federal match grade.
Parts list
Mega Machine monolithic upper/lower combo
CMC trigger group
Ambi safety lever from AR15.com
Troy ambi mag release button
Magpul MIAD grip
Magpul PRS AR10 stock
JP Rifles silent captured buffer/spring
Fulton Armory Stainless Steel match grade 18.5” barrel
JP rifles .936” adjustable gas block
AR15 rifle length gas tube
JP rifles enhanced 308 bolt
DPMS bolt carrier, cam, firing pin
YHM phantom QD flash hider
PRI AR10 gasbuster charging handle
Atlas Bipod......backordered....uggggh
Larue PSR 20MOA mount
SWFA SS 12x42 fixed power Mil/Mil scope
I have been searching for a suppressor host for my YHM phantom 30 cal can and have sampled a couple rifles. I owned a M1A socom and a cheaper FAL recently. Neither of these really rang my bell. I really didn't want to spend the cash on a high end 308AR, but bit the bullet and did it a little at a time. My goal was to build a sub moa battle rifle.
I ordered a Mega Machine monolithic uppper and ambi lower combination and all I can say is wow. This stuff is the nicest kit I have had the pleasure to get my skinners on. Fit and finish is second to none. Finish seems to be hard as hell and all corners are nicely rounded with machining transitions almost undetectable. Most of the roll pins have been replaced with threaded allens. Additionally, there is a upper/lower tensioning screw so you can fine tune the fit. The upper/lower came with detent pins, an ambi bolt release system and dust cover assembly all factory installed. The kit also came with a proprietary barrel nut and wrench for installation. Installation instructions were well written and extremely clear. Barrel installation was a breeze just as any other AR platform. The supplied barrel wrench has a provision for a 1/2" torque wrench and the instructions call out the specific torque.
For the rest of the upper build I went with a 18.5" stainless match grade barrel from fulton armory as this was the best balance of cost/performance for my needs. The gas system is rifle length with a JP Rifles .936" adjustable gas block. Bolt is a JP enhanced 308 bolt riding in a DPMS chrome bolt carrier. The charging handle is a PRI gasbuster. Prior to ordering the barrel, I sent my bolt to Fulton Armory so they could install the barrel extension and achieve the proper headspace. I would highly recommend this to anyone building a 308 for safety reasons. Another caveat on the barrel is that the fulton armory barrel threading is just a bit too long (.030” to be exact) to accommodate the YHM quick detach suppressor flash hider. I have yet to remedy this, but my plan is to have the barrel shortened by .050” and re-crowned so the suppressor flash hider will seat on the barrel shoulder. Additionally, the upper will eventually wear an Atlas bipod, but it has been on backorder going on 3 weeks now.
For the lower, I installed a CMC trigger group again a great balance of performance/cost. I run one of these in my SBR AR. Nice, crisp break and very little overtravel. I went with a Magpul UBR stock initially but just couldn't get the cheek weld I wanted with a scope, so changed it out to a magpul PRS for the AR10. The lower also wears a Magpul MIAD grip and sports an ambi safety lever from AR15.com. Another interesting part I came across that I have been more than happy with is the JP rifles captured silent buffer spring. This is a completely contained spring/buffer combination specifically for the AR308 platform (they make one for AR15 as well). It is the correct length for carbine stocks but comes with a spacer to allow it to work with rifle length buffer tubes as well. I also installed a troy ambi mag release button to stay with the ambi theme.
For glass, I went with a Larue tactical PSR one piece quick detach mount with 20 moa built into the package and SWFA's new SS 12x42 fixed power MIL/MIL scope. The scope is another great piece for the price/performance ratio. Glass is super bright and clear in low light, reticle has been well thought out and reticle subtensions/turret adjustements are both in MILs.
First impression when you pick up the rifle is that it is pretty heavy. I haven't had it on a scale yet, so exact weight is unknown.
Range report on this sukka is what one would expect from a top notch rifle in 308. First of all let me preface this with the statement that I am no expert shooter and have very little experience with precision shooting. I shot a combination of Remington match grade 168gr, Federal match grade 168gr and Federal Fusion 150gr on my first range trip. I dialed in the scope and did a little barrel break in with the first 20 rounds. I sent a couple wet patches followed by a dry patch down the bore every round for the first ten and every three rounds for the next 9. I then shot a few 5 round groups. It was hot that day (in the 90's) with a little bit of wind (prolly 10mph cross wind) and all groups were shot from a bench on bags at 100 yards. Also want to note that these were shot un-suppressed as I just received my suppressor and haven't had a chance to shoot it yet .
All three types of ammo were shot in 5rnd groups with the Federal Match grade 168 gr holding the tightest group at .610". The Federal Fusion and Remington match grouped at .910" and .795" respectively. I am sure the rifle can do better as my eyes are old and I am not the steadiest person behind a rifle even on bags and a bench. Needless to say, I am extremely happy with the performance that was demonstrated. Next thing will be to work up a handload to see if I can improve on the group I shot with the Federal match grade.
Parts list
Mega Machine monolithic upper/lower combo
CMC trigger group
Ambi safety lever from AR15.com
Troy ambi mag release button
Magpul MIAD grip
Magpul PRS AR10 stock
JP Rifles silent captured buffer/spring
Fulton Armory Stainless Steel match grade 18.5” barrel
JP rifles .936” adjustable gas block
AR15 rifle length gas tube
JP rifles enhanced 308 bolt
DPMS bolt carrier, cam, firing pin
YHM phantom QD flash hider
PRI AR10 gasbuster charging handle
Atlas Bipod......backordered....uggggh
Larue PSR 20MOA mount
SWFA SS 12x42 fixed power Mil/Mil scope
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