Posted: 4/4/2026 3:32:58 PM EDT
| I built a 6mm ARC with 22" Rainier barrel with plus 2" gas Tube. I have an adjustable gas block and have it all the way open and cannot get it to cycle good. It has a rifle length stock with stock buffer spring and A2 buffer with all weights taken out. I am using Duramag magazines and still just barely cycles. Has anybody have any suggestions on what I can do. |
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Originally Posted By G15: I built a 6mm ARC with 22" Rainier barrel with plus 2" gas Tube. I have an adjustable gas block and have it all the way open and cannot get it to cycle good. It has a rifle length stock with stock buffer spring and A2 buffer with all weights taken out. I am using Duramag magazines and still just barely cycles. Has anybody have any suggestions on what I can do. Talk to Rainer... get their advice and guidance. See what ammo was used in their testing and why they chose the +2. I'm just not a fan of the + type gas systems. Then again, I'm a 20" and under barrel guy. |
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What ammo are you running? I’m running a 22” +2 and have zero issues with Hornady 105/108’s, or my handloads. The Hornady 80 and FGMM 108 loads have issues cycling, likely due to lower port pressure. If you haven’t tried the Hornady 105/108’s, I’d start there. That’s the ammo most systems were built around. |
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Originally Posted By G15: Running 108's but got it fixed. I swapped out the bcg and std buffer and spring for a JP low mass bcg and their silent capture spring with the lightest spring. Thanks to Speyrod. Runs great now. And thank you everybody else. Glad to hear this. Enjoy! |
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I don’t understand why they are using a plus 2 gas length. I have built 6 different 6 arcs none had any extra gas lengths or adjustable gas blocks and a 20” with a plus 1. All ran fine and actually seemed a little under gassed ejecting in the 4-5 o’clock range. I’m changing out a T2 weight in an A5 system to a A0 to see if I can get it to eject a little harder in a 14.5 proof I have. Is there a need to go with a longer system that I’m not getting here? |
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Originally Posted By paigecm1: I don’t understand why they are using a plus 2 gas length. I have built 6 different 6 arcs none had any extra gas lengths or adjustable gas blocks and a 20” with a plus 1. All ran fine and actually seemed a little under gassed ejecting in the 4-5 o’clock range. I’m changing out a T2 weight in an A5 system to a A0 to see if I can get it to eject a little harder in a 14.5 proof I have. Is there a need to go with a longer system that I’m not getting here? Mostly agree with you. The one variable will be the unknown gas port size. With that said. The +2 set up like the op and mine is extremely soft shooting. I shoot a lot of mid to long range with mine and appreciate that. In general, I would not recommend a +2 unless the port is oversized or you are willing to spend the $ to set up the way we did. I really like the way mine is set up. |
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Originally Posted By paigecm1: I don’t understand why they are using a plus 2 gas length. I have built 6 different 6 arcs none had any extra gas lengths or adjustable gas blocks and a 20” with a plus 1. All ran fine and actually seemed a little under gassed ejecting in the 4-5 o’clock range. I’m changing out a T2 weight in an A5 system to a A0 to see if I can get it to eject a little harder in a 14.5 proof I have. Is there a need to go with a longer system that I’m not getting here? Like any AR it softens recoil as you lengthen the gas system. I have an intermediate 16 in 556 AR that with the gun on a bipod it literally won't move when firing. I have a video of me shooting it where you can't see the gun move. Just hear the suppressed shot. It's cool. Anyways gas port likely undersized for that gas length. |