I just ordered the rifle and was reading the internal diameter of the DD rail is 1.15" and the diameter of the can is 1.5". How far back does the can sit of the QD mount? Will there be enough room for the can? I want a 7.62 can to use on multiple platforms, but I foresee a possible problem.
Anyone have any insight or experience with this combo?
Thanks for any help!
You’re good. Rock on.
Thanks for the quick reply- the photos from Noveske do not do it justice. It appears the rail extneds to the base of the flash hider and the AAC page makes it sound like I will need almost 2" of barrel to mount the can.
Appreciate it.
The “specs” can be confusing, but 51T AAC cans do not extend passed the teeth on the flash hider for the suppressor to mount to.
You’re good with any AAC mount and that setup. Since it uses a 10.5" barrel versus the 10.3" of a “real” MK18, you’ll have no problem.
For anyone with the 10.3" version-
If you mount the can on either a BLACKOUT Flash Hider or a BRAKEOUT comp, it will work. That’s because these have maybe a 1/8" section of wrench flats behind the ratchet teeth that push the whole thing a little further out.
If you try to mount the can using a BLACKOUT Muzzle Brake or an older BRAKEOUT comp, it will not work because these have a flat back and the can will hit the rail just before it is fully tight.
I bought the DD 10.3" barrel without even thinking of clearance issues. I ordered the AAC SDN-6 and the 51t Brake mount, I had to have the brake mount for the blast baffle protection perks. It was a no go on fitting because it doesn’t have the wrench flats behind the teeth. So I had my suppressor dealer/machinist make an extra large shim/spacer to get the mount far enough away from the rail. He said it allowed for 10 threads to still be engaged, well over the minimum of 6 threads needed for good lockup. Had to use a couple of shims to rotate it to time properly. Fits great. Looks great. Works great.
I tried on my M4-2000 that’s currently pending and his Mini-4, both of them fit nicely also. Trying on the Mini-4 was a bad idea, made me want one too!
So the DD MK 18 and the sdn6 is definitely a no-go without some sort of shim/spacer?
I’m looking at this combo right now since I have the upper in hand…
Re-read the thread…
It’s a no-go with a 51t brake.
How does one of these feel on a MK18? 20oz and 6+" added seems like a lot…
I’ll let you know when I finally get my stamp in the mail. Any day now… (Sent in early November)
I’ll throw in my 2 cents for others who are exploring the DD Mk18 10.3 and SDN combo. I have a DD Mk18 and did a test fit with my SDN while it’s still in jail. I have the 51t Blackout flash hider with the wrench flats. I had to use the AAC flash hider tool to install it because the wrench flats tucked in the rail by 1-2mm (eyeballing it).
Anyway, I used the thickest shim in the AAC shim kit and the SDN cleared the rail by about 1mm. Without the shim, my SDN locked up fine, but it looked like it touched the rail. I was probably ok as-is, but I added the shim anyway for peace of mind.
Did you snap a photo?
On the DDMK18 with the 51T Flash hider I have about 1/8" clearence on the M42000. If that helps.
With the Blackout Flashhider or Brakeout it’s not an issue with a DD 10.3" barrel. The Noveske barrel was 10.5" and even less of an issue.
My DD/M4-2000 (same mounting as SDN6, just shorter/lighter can):
66871493-8eb7-4bcd-b597-c4bc290fc349 by ASH556, on Flickr
8d3a4c87-ac1b-4581-89fc-ff2e009d1b6e by ASH556, on Flickr
My DD Mk18 with AAC SDN (I used the thickest shim in the AAC shim kit):
Closer shot:
Great photo, thank you very much. Brake mount or Brakeout mount?
I have the newer Blackout flash hider w/ the wrench flats. I used the AAC flash hider tool to install because the wrench flats tucked into the rail about 1-2mm.
Factory DD MK18, SDN6, 51T Brakeout
I forgot about this thread. Protip: if you use the AAC Brake, the wrench flats are on the brake itself rather than overlapping the barrel, making it very easy to install without special tools. Another advantage is that you’ll be using shims anyway (and it comes with them), so you’ll push out a little more. And finally, it acts as a sacrificial baffle for your short barreled AR. My brake is showing erosion after about 1.5k rds, but I haven’t checked it regularly since I don’t often remove the can.