Just ordered an MK18 upper today to use for a pistol .  I know besides the over gassed issue, anyone running this on a pistol?  I might keep it a pistol if I get stationed in California because under the law, I am not required to register pistols if active duty on PCS orders, only "assault rifles".

I have a factory DDmk18 pistol.  Its runs flawless with any and all ammo. Suppressed and non suppressed.   I feel like it is properly gassed.

I'm running old school; LMT MK18.

Love it.  Good luck in the People's Republik.  I am confident the Marine Corps will just send me back to Lejeune for the 4th time.

I like mine I have the DD MK18 AR Pistol 10.3'' and it runs like a boss.

Don't listen to all that 'over gassed' BS. I built a pistol lower and put a DD MK18 upper on it and it runs like a champ. Spikes T2 buffer. 1000 rds so far, 400 of them suppressed and not a hiccup.

Yes, works good, accurate too!

I doubt if it will be over-gassed, but do have doubts whether or not Cali. would or wouldn't consider it an assault weapon.

As used in Sections 16530 and 16640, Sections 17720 to 17730, inclusive, Section 17740, Article 1 (commencing with Section 27500) of Chapter 4 of Division 6 of Title 4, and Article 1 (commencing with Section 33210) of Chapter 8 of Division 10 of Title 4, “short-barreled rifle” means any of the following:
(a) A rifle having a barrel or barrels of less than 16 inches in length.
(b) A rifle with an overall length of less than 26 inches.
(c) Any weapon made from a rifle (whether by alteration, modification, or otherwise) if that weapon, as modified, has an overall length of less than 26 inches or a barrel or barrels of less than 16 inches in length.
(d) Any device that may be readily restored to fire a fixed cartridge which, when so restored, is a device defined in subdivisions (a) to (c), inclusive.
(e) Any part, or combination of parts, designed and intended to convert a device into a device defined in subdivisions (a) to (c), inclusive, or any combination of parts from which a device defined in subdivisions (a) to (c), inclusive, may be readily assembled if those parts are in the possession or under the control of the same person.

Yeah, I think it is an "Assault Weapons ban" not the "assault rifle ban".
MrWhite, how do you own that in California? Fixed mag or something?

Bullet button!

Im running an MK18 10.3 upper as a pistol and its been perfect so far, love it.

Overgased and function aren't necessarily the same thing. The gas port itself is of larger diameter than military specification for an SBR of that barrel length. Daniel Defense did this to allow reliable function with weaker loads since not everybody can afford to shoot 5.56 spec ammunition. You using the T2 buffer decreases the chances of bolt bounce, slows down the cyclic rate and gives the magazine more time to feed, especially when suppressed.

However, while the buffer really mitigates a lot of those issues, it doesn't solve the issue of the extra amount of gas that enters the system. The system still gets dirtier faster and still burns lubrication faster. I noticed this comparatively to my LMT 10.5 that has a proper gas port. This was seen both unsuppressed and suppressed with a Saker 556.

To make a long story short, if you don't have a problem with lubing the action more frequently and cleaning more often, this is completely a non-issue if you get a heavier buffer. I had the best luck with an H2 buffer. I sold my DD MK18 upper and replaced it with a KAC SR-15 E3 CQB upper and it runs like a champ.

I really like mine.

Two thumbs up.



 

Love mine too but mine has the .070 Mil-spec gas port and not the .080 Commercial so I can't comment on the gas issue. I run mine with a Colt H2 buffer btw.







 

Got mine today the BCG had so many problems not happy

Do listen. The DD MK18 gas port IS larger than it should be (to accommodate weaker loaded commercial ammunition) and IS overgassed. That's an undeniable fact. It's not a deal breaker, however, as it can be countered with an adjustable gas block or mitigated with a heavier buffer or the Vltor A5 buffer system.

Don't hand wave it away. It is a real issue that you must consider, but it is not something that should completely restrict your buying from DD.