What's the consensus on gas tubes that restrict flow?

**okie** · 09-28-21, 20:47

I have a Mk18 that's pretty gassy suppressed. I don't want to put an adjustable on it, and want to change out the carrier even less. I've heard of some gas tubes that have a smaller hole, but I'm not sure where to find them or if they're a good idea or not.

**AndyLate** · 09-28-21, 21:14

Originally Posted by okie

I have a Mk18 that's pretty gassy suppressed. I don't want to put an adjustable on it, and want to change out the carrier even less. I've heard of some gas tubes that have a smaller hole, but I'm not sure where to find them or if they're a good idea or not.

You can find them at Black River Tactical. I have not used one of the tubes, so cannot comment on them. I can say I have found BRT products to be uniformly high quality.

Andy

**MWAG19919** · 09-28-21, 21:22

Well I can tell you where to find them, but I have no personal experience with them.

https://blackrivertactical.com/

I actually have the opposite experience with my MK18; it's gassed perfectly for its intended role (5.56 with a suppressor), but with .223 and no suppressor it's pretty anemically gassed.

**okie** · 09-29-21, 02:01

Originally Posted by MWAG19919

Well I can tell you where to find them, but I have no personal experience with them.

https://blackrivertactical.com/

I actually have the opposite experience with my MK18; it's gassed perfectly for its intended role (5.56 with a suppressor), but with .223 and no suppressor it's pretty anemically gassed.

Mine with no silencer is picky about locking back with .223. It will lock back on lancer 20 rounders, but not with Okay milspec mags. With the silencer, it will lock back with anything even running an H3 buffer. It has a .07 gas port.

If you have a DD, it might have a smaller port. I heard something about them reducing the gas port size to under milspec on theirs.

**MWAG19919** · 09-29-21, 04:38

Originally Posted by okie

Mine with no silencer is picky about locking back with .223. It will lock back on lancer 20 rounders, but not with Okay milspec mags. With the silencer, it will lock back with anything even running an H3 buffer. It has a .07 gas port.

If you have a DD, it might have a smaller port. I heard something about them reducing the gas port size to under milspec on theirs.

You're spot on. It's a newer DD with a 0.070" gas port. It locks back on my .223 reloads at the indoor range, but in colder temps it only locks back with 5.56 (and even then, ejection is sluggish). My HD load is 5.56x45mm Hornady SBR, so I'm not too concerned, but it's slightly annoying that it doesn't "like" one of my favorite .223 handloads.

No suppressors allowed here in IL, but it's at the top of my list when I get the hell out of this state.

It probably doesn't help that the gun has a Law folder (2.3 oz extra weight for the adapter plug), but I've tried all manner of buffers before settling on a VLTOR A5H0 and a standard power rifle spring.

**opngrnd** · 09-29-21, 05:01

I've also found BRT products to be excellent, and have used their has tubes to adjust gas flow. I found they worked exactly as advertised. In a different thread, one was used 5,000 rounds suppressed without issue.

**1168** · 09-29-21, 05:19

There’s a two-year old thread in technical that I posted in two weeks ago. It might still be close to the top.

I like them.

**gaijin** · 09-29-21, 05:44

I use three BRT gabs tubes in overgassed BCM Barrels; 2 - 11.5” and a 14.5”.
Mine are unsuppressed but there’s a noticeable difference in recoil impulse with the BRT Tube.
A range bud runs one with his Suppressed mk 18 and it tamed his overgassed issue.