06-26-2021, 12:35 PM
VASCAR2 Wrote:My first 6.5 Grendel upper I purchased from J&T Distributing (sister company to Double Star) was a 16 barrel with fixed front sight and carbine length hand guard. This upper was over gassed and I tried a T2 and H2 buffers but I didnt like the inconsistent ejection when I shot a variety of ammo. I finally fixed this upper to my satisfaction by using an Rubber City Armory adjustable gas carrier key. The gas port on this barrel is way to large but using the set screws in the carrier key I can throttle the gas. This upper now functions like it had the correct size gas port.
Trying different buffers helps but the root cause of my problem was the volume and gas pressure. Once I set the adjustable carrier key this upper behaves just like my other 16 6.5 Grendel with the appropriate size gas port. I have tried reloads using 85 grain, 100, 107 and 123 grains. Functioning has been gtg and my brass is in a lot better condition. I was finishing a build and needed a new bolt carrier. I bought a stripped bolt carrier and used the RCA adjustable carrier key. I moved the bolt carrier from my J&T to my new build and used the new BCG with the adjustable carrier in my J&T. This was the best and least expensive solution to this 16 upper. If I used suppressors the adjustable carrier key is not as easy to change as adjustable gas blocks. I live in Illinois where suppressors are illegal so the adjustable carrier key was suitable for my situation.
If you still have issues with your upper after trying H2 & H3 buffers the adjustable carrier key might work. I dont plan on changing my gas settings on my carrier key as it seems to function correctly regardless of my ammo.
https://www.righttobear.com/RCA-Adjustab...ad-gky.htm
I had to reread that. You used an adjustable key. I had not thought of that. If this tube does not work out that is probably the route I will go. Give me a reason to get a staking tool and swap out to some of those Forward Controls gas key screws. Thanks