Hey all. This was my first AR build. I own one carbine and one 7 inch pistol, both purchased, before I decided I wanted to try my hand at building. I’m fairly handy having modded jeeps and worked on cars before. Rifles are easy in comparison and smaller, safer and more fun too.
Michigan disallows SBR’s so this is registered as a pistol + the popular SigTac arm brace.
List of parts:
Detroit Gun Works upper and lower stripped receivers
Wilson Combat BCG
Palmetto State Armory upper and lower parts kits
Odin Works .300 AAC blackout 10.5 inch barrel w/ supplied low profile gas block
Sightmark reflex red dot and 3X fold away magnifier
Generic brand A2 flash hider, gas tube, H2 buffer and spring, free float handguard and charging handle.
Range report:
Accuracy was very good
The .300 blk is an excellent round making much bigger holes at the same amount of recoil as the 5.56
Had some growing pains. My H2 buffer and spring caused failure to feeds in subsonic ammo so I bought the Nemo .300 blk spring. That worked well with the subsonics. No further issues after. It didn’t work well with supersonics at all. Cycled way too fast. Missed extractions, jammed feeds, etc. switched back to the H2 spring.
H2 spring worked better with the supersonics but had failure strip a new round sometimes. I’m thinking it’s way too strong.
I have a standard carbine buffer and spring on order. I’ll see if it will cure my supersonic ails. I’m all set for subsonic with the Nemo springs; at least until I get a can.
Sighting in my red dot at 25 yd…
This gun is nice and accurate and I’m happy to have a custom gun that is truly mine. Now I have to learn to reload because factory 300 ammo is way too expensive!
Just cut a bit off the stock spring. That’s what I did & problem solved! Take a bit off at a time til problem solved. I’ve done same fix with other sbr’s…
So I solved the issue shortly after my OP by switching to a standard carbine buffer spring coupled with a H2 buffer. That did the trick for supersonic loads.
For subsonic, I switch the buffer spring to the Brownell’s .300 AAC blackout spring tailored for subsonic rounds. That cycles like a charm now too.
The pistol also received a facelift. Upgraded the rail to a Troy Alpha, added splashes of FDE to it, swapped the MOE grip for a MIAD grip (which is awesome), flip up MBUS sights and a CMC 3.5 lb trigger. That CMC trigger is unreal. Every AR should have one!
Here are some pics of my Detroit Gun Works custom as it sits today.
