DD Mark 18 Blowback Issues

[kmc0929]

DD Mark 18 W/AAC-M42000

I used an ACOG so unfortunately my face typically has to be right up against the charging handle. The Gas Blowback is just too much, after 5 consecutive rounds I have yet to find anyone who can push through it.

I have added a Gemtech SBC; PRI Gas Buster, and the H2 buffer.

My last shot will be a heavier H3 buffer... Any other suggestions?

[tylerw02]

Have you considered an adjustable gas block?


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[bighawk]

The DD MK18 barrels are very generously gassed.

My DD MK18 wears the AAC 556SD full time and Has a Micro MOA Govnah gas block designed specifically for the DD MK18 barrel.

I run it with an H2 and a blue springco with the gas port set to .052 and functions 100% with the can. Gas to the face is minimal and very tolerable

[Slippers]

It doesn't help that you're running a m42k either. That's a gassy can. Definitely try the H3 and consider an adjustable gas block.

Obviously this doesn't help you right now, but DD can custom build an upper with a crane spec port if you ask.

[Hero]

Have you considered an adjustable gas block?


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Best decision I made.

[markm]

The DD MK18 barrels are very generously gassed.

Yeah. I'd guess that port is .080 or greater. Which is already WAY TOO MUCH gas for a non suppressed weapon. An insertable port or adjustable block is mandatory here.

[bighawk]

Best decision I made.

Without a doubt.. Mine appears to bleed off a fair amount of excess gas at the port so its pretty mild to the face.

[bighawk]

Yeah. I'd guess that port is .080 or greater. Which is already WAY TOO MUCH gas for a non suppressed weapon. An insertable port or adjustable block is mandatory here.

I recall reading they are .081/.082 which seems crazy

When its time to replace it I will get a barrel with the proper gas port size.

[nate89]

For those who have tried both, is an adjustable gas block or insert a better option? I assume the adjustable gas block has the advantage of turning down the gas with the can on to the point where it would not work reliably with it off, and being able to turn it back up when the can is off. I like the simplicity of the insert, and would be more reliable in theory. I suppose the best option is getting a barrel that is gassed correctly..

[jackblack73]

Have you tried the silcone caulk on the charging handle trick?