AR Gassing help

[Island_Mando]

Hi yall, just to start off my current setup is a 16" BCM upper with a Geissele 42 super braided wire buffer spring with a H2 buffer & radian raptor sd charging handle.

Just got a Surefire RC3, went to the range today to put some rounds through it and get some training in. Noticed with the can on, it is a bit gassy with a 2 o'clock to 3 o'clock ejection. Majority at 2 o'clock. What can I do/ what do you all recommend to change up to improve my gassing and injection pattern.

I know I could do with a adjustable gas block but I'm saving that for my absolute last resort, and seeing my options in the mean time

 

[VargmatII]

From my small experience, heavy buffers helps a little bit and an AGB solves the problem. So put an AGB on it and youll be good to go.

 

[csg2023]

Don't go adjustable gas block. Put in a H3 buffer, RTV seal your charging handle and your good. Your getting 2-3pm ejection, thats not over gassed. On a clean gun a 2pm ejection is perfect. You have to give yourself some lee way so that once your 300 rounds in your ejection backed up to the 3-4pm your still running. If you start with a 4pm ejection your carbine is not running after 300, potentially. You could have a 5pm ejection and still get gas to the face if you're giving that gas a "way out" via the charging handle.

 

[wvfarrier]

I have recently seen some fellas running charging handles with directional gas ports built into them. They push the gas either left or right of the shooter, depending on your selection

 

[csg2023]

PRI has done this for years. In my experience you will still get a bit of gas coming up towards your nose until you create a perfect seal. I RTV all my PRI charging handles and they work great.

 

[supercorndogs]

Just put an adjustable gas block on it. Easy solution.

 

[csg2023]

He dosent have an over gas issue...adjustable gas blocks are there to adjust your bolt unlock timing. They don't prevent excess gas from coming up through the charging handle. He's getting 2-3pm ejection and running a rc3......

 

[csg2023]

Think of it like this, your gun is cycling fine. That's not the issue. Your getting gas to your face, thats an issue. Why would you solve a gas to the face issue by adding another component to your gun that will fail unless regularly maintained, for one, and two all its going to do is further delay your bolt unlock timing bringing your gun closer to a eventual failure point.

 

[supercorndogs]

He dosent have an over gas issue...adjustable gas blocks are there to adjust your bolt unlock timing. They don't prevent excess gas from coming up through the charging handle. He's getting 2-3pm ejection and running a rc3......

Adjustable gas blocks are there to reduce gas to your bolt. Adjustable gas blocks restrict gas flow. You can put what ever glue whereever you want on yours. I have regular charging handles, high back pressure cans, adjustable blocks, and don't get gas in the face.

Ejection angle doesn't always tell the tale. I would say the gas in the face while using a low back pressure can is the other peice of the story you are missing here. I have seen more than one go from 3-4 ejection back to 1-2 then back to 3-4 again as I turned the gas down. Probably the reason most blocks have you adjust by lock back and not ejection angle.

 

[csg2023]

That's cool man. Im not saying it wont solve the problem, im just saying it's the wrong way. To say a gun with a h2 and a RC3 needs an adjustable gas block when hes getting 2-3pm ejection already is just plain wrong. But yeah, go ahead and put an additional component on your gun that regularly fails instead of just creating an air tight seal for 5$ like people have been doing for years.....

 

[Obi-WanKannoli]

Switch an A5 buffer system. The BCM Mk2 is great. I run mine with an A5 tube, G$ super42 rifle spring, and BCM Mk2 T3 buffer on a suppressed 10.5. An adjustable gas block will be a huge help too, I am a fan of the Superlative Arms venting gas block after running them on a few builds.

Edit:

Gas Busting charging handles are a band aid for a bullet hole by the way....but get one of those anyway.

 

[Ronws]

My Windham Weaponry R16SFST-308 (AR-10) has a fixed mid-length gas block.

I had changed from telescoping carbine stock to a rifle tube and put on the Magpul PRS Gen III adjustable stock.

Only problem, unknown at the time, was that the buffer was too light for the 168 gr I was firing and I was getting double feeds and jams.

I had two other buffers laying around. Took them apart and mixed and matched the weights to get more weight to slow down the cycle. 6.1 ounces seens to do the trick. However, being at an inside range, I use a brass catcher so I don't know if it is at 2 or 3 o'clock. I just know that it is ejecting and feeding fine.

And that is all of my knowledge and experience, to date. I could imagine having a tunable block adds more factors to the solution.

 

[msgriff]

You can try a heavier buffer, but if you're going to stick with the Geissele 42 carbine spring, you have to use their buffers. You can also swap out the remaining steel weight in your H2 to a tungsten weight. Geissele does sell replacement tungsten weights, which I believe are slightly smaller OD to fit their buffer bodies.

 

[Jsp556]

Chasing perceived perfect ejection patterns or just the right recoil impulse at the expense of reduced reliability is a bad trade.

 

[Stone111]

Hi yall, just to start off my current setup is a 16" BCM upper with a Geissele 42 super braided wire buffer spring with a H2 buffer & radian raptor sd charging handle.

Just got a Surefire RC3, went to the range today to put some rounds through it and get some training in. Noticed with the can on, it is a bit gassy with a 2 o'clock to 3 o'clock ejection. Majority at 2 o'clock. What can I do/ what do you all recommend to change up to improve my gassing and injection pattern.

I know I could do with a adjustable gas block but I'm saving that for my absolute last resort, and seeing my options in the mean time

Its not broke, dont fix it... It runs well supressed and unsupressed why frack with it?

 

[Cascade Hemi]

The easiest solution is probably a Bootleg carrier, if the OP doesn't want an adjustable gas block. The ideal solution, and probably least viable, is a smaller gas port. All of the springs, buffer weight, extended buffer tubes, and glue are just work arounds for what is a gas system issue. If you really want to mess around with the buffer I'd stick with Sprinco springs and regular carbine buffers/weights.

People just really like doing things the hard way though.

 

[bfoosh006]

While more expensive then a Adj. GB.. there are "improved design" BCG's.
How much do they help ? I don't know.

Lantac
https://www.lantac-usa.com/product-page/enhanced-bcg-full-auto-style-223-5-56-nitrided

CMC / SanTan 5.56 BCG
https://cmctriggers.com/product/cmc...sor-optimized-milspec-black-nitride-5-56-223/

 

[Island_Mando]

Thanks for all the input yall, I'm definitely going to test out going with a heavier buffer and an adjustable bolt carrier

 

[flogxal]

You can also get an adjustable gas key from Rubber City Armory, if you are comfortable doing gas key swaps. Then you can adjust through the ejection port just like with the Bootleg adjustable BCG.