uvausmc
Member
Just got done test firing my new .300 AAC Blackout build.
The rifle started off as a basic M1S carbine upper on a Stag lower. Over the years I had fixed it up with Magpul CTR stock, MIAD grip, MI extended forearm and optics. I've been reading a ton about the .300 BLK and have a few 5.56 AR's so I decided to convert one.
I changed the barrel to a CMMG .300 BLK 16" barrel with an AAC Blackout Muzzle Brake. I also switched to a YHM flip up front sight gas block. The rifle turned out great! Function was flawless with Remington 115gr FMJ ammo. all brass landed about 6 feet away at 4 o'clock in a nice neat little pile. Recoil was like shooting 5.56 and the muzzle blast was not any noticeably louder.
I also shot some handloads with 110gr Hornady SP over 15.1 gr of 2400 but these were too light. They would chamber, fire, and eject fine but did not push the bolt back far enough to pick up the next round. I'm going to bump up the charge and try again but they should result in a great inexpensive plinking load.
The factory load chrono'd and average of about 2200 fps and the handloads were just over 2060 fps. I didnt shoot for groups but accuracy off hand was a few inches at 50 yds with the dot sight.
Now I just need to get my AAC 7.62-SD and the setup will be complete.
Total cost of the project was $350 for the parts and was definitely worth it.
The rifle started off as a basic M1S carbine upper on a Stag lower. Over the years I had fixed it up with Magpul CTR stock, MIAD grip, MI extended forearm and optics. I've been reading a ton about the .300 BLK and have a few 5.56 AR's so I decided to convert one.
I changed the barrel to a CMMG .300 BLK 16" barrel with an AAC Blackout Muzzle Brake. I also switched to a YHM flip up front sight gas block. The rifle turned out great! Function was flawless with Remington 115gr FMJ ammo. all brass landed about 6 feet away at 4 o'clock in a nice neat little pile. Recoil was like shooting 5.56 and the muzzle blast was not any noticeably louder.
I also shot some handloads with 110gr Hornady SP over 15.1 gr of 2400 but these were too light. They would chamber, fire, and eject fine but did not push the bolt back far enough to pick up the next round. I'm going to bump up the charge and try again but they should result in a great inexpensive plinking load.
The factory load chrono'd and average of about 2200 fps and the handloads were just over 2060 fps. I didnt shoot for groups but accuracy off hand was a few inches at 50 yds with the dot sight.
Now I just need to get my AAC 7.62-SD and the setup will be complete.
Total cost of the project was $350 for the parts and was definitely worth it.
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