Anyone running a DDMK18 Suppressed?

The MK18 was designed by Crane to run suppressed properly. It has a lot of work and a lot of .gov ammo put through it to make it roll well.

We shoot a MK18 at work a lot (DD) and its fine. I also shoot a DD 10.3 barrel in one of my rifles suppressed a lot and it doesn't give a shit.

That said, if you feel the need adjustable gas/ a BRT tube / an adjustable gas key can help with locking times. But it for sure was meant to be shot suppressed and work OK>.
 
The MK18 was designed by Crane to run suppressed properly. It has a lot of work and a lot of .gov ammo put through it to make it roll well.

We shoot a MK18 at work a lot (DD) and its fine. I also shoot a DD 10.3 barrel in one of my rifles suppressed a lot and it doesn't give a shit.

That said, if you feel the need adjustable gas/ a BRT tube / an adjustable gas key can help with locking times. But it for sure was meant to be shot suppressed and work OK>.
This is exactly what I was thinking! Thanks guys!
 
I’ll circle back a minute.

It’s easy to tune an AR to work suppressed. It works better when you leave it suppressed.

Buffer weight
Gas system
BCG type

These 3 tune almost any AR to run with a can.

Some barrels are over gassed AF to add reliability when fouled. These barrels suck with a can, but you turn them down with a gas block or a suppressor type BCG like a bootleg and everything is forgiven.

If I’m always changing between can and no can I like a piston gun with a 2 setting gas block. LMT comes to mind.
 
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I’ll circle back a minute.

It’s easy to tune an AR to work suppressed. It works better when you leave it suppressed.

Buffer weight
Gas system
BCG type

These 3 tune almost any AR to run with a can.

Some barrels are over gassed AF to add reliability when fouled. These barrels suck with a can, but you turn them down with a gas block or a suppressor type BCG like a bootleg and everything is forgiven.

If I’m always changing between can and no can I like a piston gun with a 2 setting gas block. LMT comes to mind.
These will be permanently canned. The older I get the more l like shooting suppressed. I was hoping to get by without running an adj gas block. With that said, I agree piston gun suppressed are the shiznit imo.
 
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I run a DD 10.3 (5.56) suppressed with the 9mm (black) buffer. Sweetest shooting SBR I've ever owned. No adjustable GB, runs in FA too without issue. Does not seem to care if the suppressor is on or off!
 
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Keep in mind with the dd mk18 upper if it's a older barrel (I don't remember the year) they used a large .78 or .83 gas port. Later on they downsized it to a much better .72 or similar. The older larger gas port versions were a beast to tame suppressed but mine was the smaller port version and was fine with just a buffer swap.
 
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The RRA 9mm buffer weighs 5.5 oz. I carry a complete set of buffers when testing which allows me to find the best one for a particular weapon. As a side note, the registered SBR lower sees several uppers of different configurations and they all run with that 9mm buffer so I'm gonna guess that the gas port was oversized from DD when I bought it. I usually measure before assembly but I can't remember what this one was/is.

Almost forgot..... the dimensions of the RRA 9mm buffer are the same as a 5.56 buffer. Some are larger but not the RRA.
 
Keep in mind with the dd mk18 upper if it's a older barrel (I don't remember the year) they used a large .78 or .83 gas port. Later on they downsized it to a much better .72 or similar. The older larger gas port versions were a beast to tame suppressed but mine was the smaller port version and was fine with just a buffer swap.

It is down to 0.70" as of 2018 production forward. Anyone with an order barrel that will shoot suppressed should get a new DD or Colt barrel
 
I shoot the piss out of mine, it's at 2018 upper that has seen 5-6K rounds with about 95% of those running a can. It's been shot until it's damn near too hot to hold with a m16 lower and I haven't had any issues. Around 4-4.5K rounds I did rebuild the bolt and put a fresh buffer spring in it, nothing looked damaged, but the extractor was looking worn so I figured why not.

I've run mostly m855 or the frontier 75gr 5.56 load (works great on pigs). It will cycle the steel case stuff just fine with the can on, but ejection is a little weak without it.

I'm a lefty so I do eat a little gas running it, but it's not enough to really bother me unless I'm at an indoor range. I'd say go for it, mine has been great, only thing to watch is clearance between the back of your can and the handguard. I'm running a SDN6 that had it's ass chopped off and converted to cherry bomb brake and the gap between can and handguard is tiny. Good luck!
 
I have one and an wondering if I will encounter any issues running a factory built MK18 suppressed. I’m not anticipating any but was curious if anyone else has had any issues with that set up?
I have a DD MK18 circa 2011 with the larger gas port, it is the most reliable rifle I own and cycles everything. It is not the most pleasant shooting rifle. I changed the muzzle device to the Dead Air flash hider and I switched cans to the Sandman S. My current setup is the MK 18 with a Geissele flat spring and H3 Buffer, PRI Gas Buster charging handle and the Sandman S. I get 3 o'clock ejection and significantly less gas in my face then when I used a 556 can.
 
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I would rather a 11.5" or 12.5" than a MK18 clone.

Much better shoot ability, reliability and less wear/tear on gun. Don't have to overgas the piss out of it to keep it running in adverse conditions.
Yes this is sort of my dilemma and why I asked about price for one over the other. I may offload some and am trying to figure out what to keep. It comes down to 10.3”, 11.5” or 12.5”. All the rest are 16” or 20”. Eh, maybe I keep them all. I rarely sell stuff unless it just doesn’t run.
 
I have a DD 10.3” barrel with the .070” gas port. It’s suppressed with a SilencerCo Saker. I installed a BRT gas tube for suppressed only use, it’s no longer gassy and insanely smooth.

I also use the LMT enhanced carrier, and Vltor A5 buffer system. I’ve had no reliability issues.
 
I would rather a 11.5" or 12.5" than a MK18 clone.

Much better shoot ability, reliability and less wear/tear on gun. Don't have to overgas the piss out of it to keep it running in adverse conditions.
I actually think that over gassed rifles are more likely to cycle in adverse conditions. I 100% agree with the wear and tear aspect though so maybe that is the trade off.
 
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I actually think that over gassed rifles are more likely to cycle in adverse conditions. I 100% agree with the wear and tear aspect though so maybe that is the trade off.
All things being equal this is true, there are a bunch of levers and and its a balancing act.

An over gassed SBR sucks to shoot. Stick a Can on there and it only gets worse.

Having a lower dwell, not needing as much gas, smoother shooting, better ballistics all while being MORE reliable is a no brainer and why the 11.5 and 12.5 are king for those in the know.
 
I would rather a 11.5" or 12.5" than a MK18 clone.

Much better shoot ability, reliability and less wear/tear on gun. Don't have to overgas the piss out of it to keep it running in adverse conditions.
As others have stated already, I certainly agree about shootability and parts wear and tear, but the DDMK18 is definitely a reliable weapon.
 
One consideration, when suppressed, every inch of barrel sticking out counts. But, the shorter the barrel the harder it is on the suppressor too! Regarding overgassing (within reason), other parts are relatively cheap so a little more reliability is a fair trade IMO.
 
I think the question to ask yourself is what is intended use for the rifle.

I went with a mk18 upper because I wanted short and reliable, the cons of going with that upper are that it's gassy and hard on parts...the pros of that upper is that it just flat out runs. I was willing to take the cons because for me the pros were what I was after. The upper spends alot of time in the ranger, tractor, truck ect, I don't fret over it being dusty, getting rained on ect, if I need it I know it will run.

If your chasing smooth running, but still short the 11" and 12" upper are smoother for sure. A 12.5" midlength is an absolute caddy to run, but the one I had for a while took several combinations of buffers/springs ect to run just right.

If you don't want to screw around and don't mind a little harsher recoil (it's 556 harsh is a stretch) I say go mk18.
If you don't mind a little tinkering a 12.5" middy with a can is HARD to beat.

Good luck bud!
 
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I used the Geissele URG-1 10.3"upper with a Griffin RECCE can never had an issue gas blowback is minimal. Occasionally the need to resort to a glove
hand guard gets a little warm, fucking hot TBH.
Then there is the 12.5" that has a can I made this is the softest shooting rifle I have, 400-500 yards with the Eotech is easy. As above a little gas blow back
Neither has a AGB
 
I do. A bit over gassed with my 5.56 Surefire SOCOM but, as long as you are not doing mag dumps, it won't be too trashy.

I have since SBR'd this rifle and put a DD stock on it.

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The 10.3 is currently my favorite AR setup, even over my suppressed 16” KAC.
I’ve currently got a 10.3 Andro pistol with the .070 gas port and Surefire SOCOM brake. Hands down my favorite right now. It goes bang and the muzzle doesn’t move at all, zero recoil too. I guess as quite surprised the first time out with it.

I’ve been eyeing up the MK18 for a while after shooting the Andro.
 
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Well, just ordered the FDE handguard model directly from DD. I’m gonna put a SF SOCOM brake on it as it will pretty much only be ran suppressed. I actually really like the brakes, didn’t seem that obnoxious on my other 10.3.

Likely pick up a H2 or H3 buffer.
 
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I've been using the RRA 9mm buffer (black, 2-piece) since 2006 in my carbine without any issues. It weighs 5.5 oz so it is slightly heavier than H3. No issues at all.

What did Crane NSWC do to the MK18 to make it run suppressed without excessive blowby/gassing of the operator?
 
In my experience it’s not. As was mentioned in previous posts in this thread, if the gun is over gassed to begin with, adding a can will only make it worse.

JUst asking because I ran my YHM T2 on a 16" carbine-length DI upper and it wasn't too bad. I am waiting on a Form 1 approval so I can run a 10.5" upper, and wasn't sure if the T2 would be too "gassy" for the 10.5"