Daniel Defense MK18 Gas Port Info

[JulyAZ]

The New Daniel Defense MK18 barrels are ported at .072, and if you already have one of the overgassed barrels, Daniel Defense will replace the over gassed barrel with a .072 barrel.

[Naphtali]

I have two generally unmodified DD Mk 18s purchased in 2015. Both have ~ 700 rounds of exclusively high quality mil-spec ammo run through them. They have been run suppressed with Surefire SOCOM Mini 5.56 suppressors. I'm assuming I have the standard oversized gas ports.

My experience has been no detectable gas blowback for these 1400 rds over the two Mk 18s. And that's firing hundreds of rounds at a time at carbine courses, where other people with different suppressed carbines (16" of all types) were sporting black powder mustaches on their faces / wiping their eyes throughout the day.

FWIW, this problem appears to be fully solvable by running a Surefire SOCOM 5.56 suppressor. These were engineered specifically for the Mk 18 platform to drastically reduce gas blowback, which is a major reason they won the govt contract to supply suppressors (to mil or LE or both - not sure) for the Mk 18.

Given the above, would there be any reason for me to consider swapping barrels for a smaller port size? I don't know what it would be. As an aside, I ran all these rounds using the standard factory spring and H buffer. I've since put H2's in both, as I was told it should cycle more reliably if I slowed it down, but I just went 1 step heavier, as it already worked perfectly with the H buffers running Federal XM855 and M193.

[wirides]

The New Daniel Defense MK18 barrels are ported at .072, and if you already have one of the overgassed barrels, Daniel Defense will replace the over gassed barrel with a .072 barrel.

Can you provide evidence to back this?

Sent from my SM-G900R4 using Tapatalk

[JulyAZ]

Can you provide evidence to back this?

Sent from my SM-G900R4 using Tapatalk

https://www.m4carbine.net/showthread...MK18-amp-DD-CS

[Clint]

If they're working great, drive on.

If you wanted to experiment, send one of the two uppers back for the barrel swap and see which odds runs nicer.

Given the above, would there be any reason for me to consider swapping barrels for a smaller port size? I don't know what it would be. As an aside, I ran all these rounds using the standard factory spring and H buffer. I've since put H2's in both, as I was told it should cycle more reliably if I slowed it down, but I just went 1 step heavier, as it already worked perfectly with the H buffers running Federal XM855 and M193.