03-18-2019, 03:35 AM
Believe it or not, after taking over three years I finally built this rifle. It did take more time than a typical AR15 build due to the Adam Arms piston system, but it all came together nicely.
![[Image: 6-5-Grendel-AR15.jpg]](https://i.postimg.cc/jS1Qc5m4/6-5-Grendel-AR15.jpg)
The fluted barrel and light weight Adams Arms piston system help make for a pretty light rifle. I expected it to be somewhat front heavy, but it's really not.
I took it out today and put 180rds of Wolf 100gr FMJ through it. I started with an RZE Unimag (runs 7.62x39 100%). Unfortunately, I had a double feed during the second magazine, so I changed over to using an ELander magazine. It ran 100% after that. I put a total of 80rds through it in semiautomatic. Ejection was only about 6' away in to an area with a 2' diameter and I was using a regular carbine buffer, so this rifle is definitely not overgassed.
I then put the upper half on my M16A1 lower half. The M16A1 has an H2 buffer installed. Because of this, I figured that it might short stroke. Sure enough, this happened about five times. Ejection was only about 4'. I then replaced the H2 buffer with the regular carbine buffer. The ejection distance did increase. Unfortunately, a few cartridges failed to fire due to carrier bounce. To be fair, the Adams Arms installation instructions warned about this happening in full auto if using a regular carbine buffer. Their solution was to use an H2 buffer. Next time I'll try an H1 buffer to see if it will work. Perhaps it will work in the gap between a regular carbine buffer and an H2 buffer.
The fluted barrel and light weight Adams Arms piston system help make for a pretty light rifle. I expected it to be somewhat front heavy, but it's really not.
I took it out today and put 180rds of Wolf 100gr FMJ through it. I started with an RZE Unimag (runs 7.62x39 100%). Unfortunately, I had a double feed during the second magazine, so I changed over to using an ELander magazine. It ran 100% after that. I put a total of 80rds through it in semiautomatic. Ejection was only about 6' away in to an area with a 2' diameter and I was using a regular carbine buffer, so this rifle is definitely not overgassed.
I then put the upper half on my M16A1 lower half. The M16A1 has an H2 buffer installed. Because of this, I figured that it might short stroke. Sure enough, this happened about five times. Ejection was only about 4'. I then replaced the H2 buffer with the regular carbine buffer. The ejection distance did increase. Unfortunately, a few cartridges failed to fire due to carrier bounce. To be fair, the Adams Arms installation instructions warned about this happening in full auto if using a regular carbine buffer. Their solution was to use an H2 buffer. Next time I'll try an H1 buffer to see if it will work. Perhaps it will work in the gap between a regular carbine buffer and an H2 buffer.