9mm SBR 3-lug or direct thread?

[CanOfWhooppass]

I built my first QC10 9mm AR with a 3-lug and TROS barrel because I was under the belief that a direct thread would keep getting loose and I run rapid courses and can't keep retightening.

I'm building a second now and since one of them is suppressor under handguard and will only be removed for cleaning, I want a fact check on the direct thread option. I'd be willing to use a blue thread lock or Teflon tape, etc if that is the key.

So QD aside, is direct thread reliable for a couple hundred rounds unchecked? My 3-lug has never been an issue.

[AlabamaPaul]

I wouldn't run any direct thread can for a couple of hundred rounds without checking. If you don't want to pay the price for the TROS, get a Ballistics Advantage barrel and a screw on 3 lug adapter.

[thecameraman79]

I don't find the direct thread cans coming lose like some others have mentioned on fixed barrels. I don't run hundreds of rounds through it without checking though. Out of curiosity why not just run it with the 3 lug since you already have the 3 lug mount?

[JC in SC]

At some point, everything is direct thread to the barrel, so what is the issue with direct thread suppressors? Why are they prone to loosening, but muzzle devices are not?

[thecameraman79]

Muzzle devices are typically fixed to the barrel via a locking compound (locktite, rockset, etc.) while suppressors are not so they can be removed and placed on another host weapon easily.

At some point, everything is direct thread to the barrel, so what is the issue with direct thread suppressors? Why are they prone to loosening, but muzzle devices are not?

[CanOfWhooppass]

Money isn't a factor and the original plan was buy a second 3-lug. What's atractive to me about direct thread is on an Omega 9k the direct thread adapter is much shorter than silencerco 3-lug. I know GA 3-lug can also fit, but I'd perfer to not cross manufacturers.

Think I'm going 3-lug, thanks for the feedback.

[quiettime]

I know GA 3-lug can also fit, but I'd perfer to not cross manufacturers.

Yeah I mean, everyone knows you can't put Autolite spark plugs in your Chevy

[thecameraman79]

I pose this question. The omega 9k with the tri lug mount vs DT mount the tri lug would be longer sitting on a table. Now mount it to the weapon using both options. Is one really longer or that much longer then the other? The tri lug sits more over the barrel so I would bet they are just about the same when it comes down to it. I have an octane 9 with the tri lug and the piston mount and I'm going to see what OAL I get for my MP5K with the tri lug and the DT and see if it is really any longer with one vs the other.

Money isn't a factor and the original plan was buy a second 3-lug. What's atractive to me about direct thread is on an Omega 9k the direct thread adapter is much shorter than silencerco 3-lug. I know GA 3-lug can also fit, but I'd perfer to not cross manufacturers.

Think I'm going 3-lug, thanks for the feedback.

[CanOfWhooppass]

I pose this question. The omega 9k with the tri lug mount vs DT mount the tri lug would be longer sitting on a table. Now mount it to the weapon using both options. Is one really longer or that much longer then the other? The tri lug sits more over the barrel so I would bet they are just about the same when it comes down to it. I have an octane 9 with the tri lug and the piston mount and I'm going to see what OAL I get for my MP5K with the tri lug and the DT and see if it is really any longer with one vs the other.

Money isn't a factor and the original plan was buy a second 3-lug. What's atractive to me about direct thread is on an Omega 9k the direct thread adapter is much shorter than silencerco 3-lug. I know GA 3-lug can also fit, but I'd perfer to not cross manufacturers.

Think I'm going 3-lug, thanks for the feedback.

Good point 3-lug swallows about 1.5" of barrel where direct thread about .5" total. They both take what they give roughly. The GA 3-lug ads about .5 and swallows 1.5 so that is the shortest option.

[thecameraman79]

That's what I figure, it's probably a wash once it attached to the host. the GA is the shortest option but then I'm not a fan how close it puts the muzzle to the blast baffle on the silencerco cans since they weren't designed for the internal tri lug like the GA cans are. The Omega 9K could probably hold up fine since it's designed for 300 BLK supers but I'm guessing the sound suppression would be hurt with the GA tri lug vs the silencerco tri lug and the 9k is already a small can.

I pose this question. The omega 9k with the tri lug mount vs DT mount the tri lug would be longer sitting on a table. Now mount it to the weapon using both options. Is one really longer or that much longer then the other? The tri lug sits more over the barrel so I would bet they are just about the same when it comes down to it. I have an octane 9 with the tri lug and the piston mount and I'm going to see what OAL I get for my MP5K with the tri lug and the DT and see if it is really any longer with one vs the other.

Money isn't a factor and the original plan was buy a second 3-lug. What's atractive to me about direct thread is on an Omega 9k the direct thread adapter is much shorter than silencerco 3-lug. I know GA 3-lug can also fit, but I'd perfer to not cross manufacturers.

Think I'm going 3-lug, thanks for the feedback.

Good point 3-lug swallows about 1.5" of barrel where direct thread about .5" total. They both take what they give roughly. The GA 3-lug ads about .5 and swallows 1.5 so that is the shortest option.