SIGforum
3 lug adaptors

This topic can be found at:
https://sigforum.com/eve/forums/a/tpc/f/380105858/m/3050060794

December 16, 2022, 06:33 PM
Tiger 2 Tank
3 lug adaptors
Hello,
I am really new at suppressors. I am building an SBR Scorpion and want to eventually put a suppressor on it. I want a 3 lug adaptor, so my question is; are all three lug adaptors the same?

Probably a very easy thing to see, but just want to make sure.
December 16, 2022, 06:42 PM
Dwill104
To be clear, you’re asking about the 3 lug mount that is attached to the muzzle, not the 3 lug adapter that goes on the rear of a suppressor, right? If so, they should work if they are designed to HK spec. Personally, I use the HK Parts 3 lug mounts, but there are others that work. A lot of people seem to like the ILWT ones. Might be easier to ask for ones that have problems, or ask about a specific mount you want to buy.
December 16, 2022, 06:58 PM
hrcjon
To expand a bit on Dwill104. From the point of 3 lug on 9mm provided its HK spec they are all the same in terms of suppressor mounting on the gun side, that's the actual point. But when buying one you have to match the barrel end of the adapter to the threads on your barrel (on a scorpion this is a generational issue) and many vendors also offer a 3 lug adapter that is 3lug and also have 1/2x28 threads at the same time. I don't like these FWIW, but many seem happy and they are more universal in the sense of you could mount something that doesn't offer a 3 lug mount on the suppressor side. I've used a number of different mfg. and really noticed no material difference. I like the rugged ones since they have the go/nogo markings and the ILWT ones. But they all are essentially the same under the covers.


“So in war, the way is to avoid what is strong, and strike at what is weak.”
December 16, 2022, 07:56 PM
Tiger 2 Tank
Sounds like what I thought. I was thinking of getting the HB Industries “HK 3 lug adaptor”. I wanted a silencer that would attach to that instead of threading a silencer on.

I guess my question is, will that lug work on any of the suppressors that attach by a 3 lug adaptor?

One more question: How is one secured on the end of the barrel? Loctite?

Thanks in advance.
December 16, 2022, 08:00 PM
Dwill104
quote:
Originally posted by Tiger 2 Tank:
Sounds like what I thought. I was thinking of getting the HB Industries “HK 3 lug adaptor”. I wanted a silencer that would attach to that instead of threading a silencer on.

I guess my question is, will that lug work on any of the suppressors that attach by a 3 lug adaptor?

One more question: How is on secured on the end of the barrel? Loctite?


It should. Personally, I just torque my 3 lug mounts on. Don’t use loctite.
December 16, 2022, 08:07 PM
Tiger 2 Tank
How much torque do you use?
December 16, 2022, 08:09 PM
hrcjon
I've never heard of any suppressor 9mm 3 lug mount not working with an HK spec 3 lug adapter (45 cal and other 3 lug designs are not covered in that). I have personally experienced a barrel machined with 3 lug that won't mount a certain suppressor, but that's really a mfg. defect in my mind.
I don't ever have any intention of removing a 3 lug adapter once mounted so I use red high temp loctite.


“So in war, the way is to avoid what is strong, and strike at what is weak.”
December 16, 2022, 08:16 PM
hrcjon
I torque mine to 20ftlb's. But in reality the problem on the CZ is holding the barrel so just a bit more than snug with some loctite will be fine.


“So in war, the way is to avoid what is strong, and strike at what is weak.”
January 04, 2023, 04:58 PM
neex
I got a Rugged Obsidian last year and---because the can came with a gift card promo for the Rugged website--I picked up one of their 3-lugs. It's HK spec, but has visual markings to help confirm the can is mounted properly. At first I found this gimmicky. After using it, though, I've come to appreciate it.
May 20, 2023, 06:44 AM
IndianaBoy
quote:
Originally posted by neex:
I got a Rugged Obsidian last year and---because the can came with a gift card promo for the Rugged website--I picked up one of their 3-lugs. It's HK spec, but has visual markings to help confirm the can is mounted properly. At first I found this gimmicky. After using it, though, I've come to appreciate it.


I also have a Obsidian on a 9mm AR and used a 3 lug mount. It is, IMHO, the only way to go with a 9mm PCC. There is no way it can work loose, as opposed to direct thread, which always seems to loosen up. I have heard of people using teflon tape to keep them snug, that sounds like a PITA to me. The peace of mind of not having to worry about a can loosening up and causing a baffle strike is well worth the cost of the 3 lug mount and adapter.

Every time I shoot my can with a booster on my Glock 45, it loosens up after a few mags. I haven't taken steps to resolve this yet as the can lives on the AR PCC and I just got the stuff for a pistol just because.
May 20, 2023, 06:45 AM
IndianaBoy
quote:
Originally posted by Tiger 2 Tank:
Hello,
I am really new at suppressors. I am building an SBR Scorpion and want to eventually put a suppressor on it. I want a 3 lug adaptor, so my question is; are all three lug adaptors the same?

Probably a very easy thing to see, but just want to make sure.

If I recall correctly, the Rugged suppressor 3 lug mounts are built to the same dimensions and standard as the original HK 3 lug, and as such are interchangeable.
May 20, 2023, 06:50 AM
IndianaBoy
https://ruggedsuppressors.com/product/3-lug-adapter/


The Rugged 3 Lug is made to HK spec, per their website.
July 21, 2023, 01:32 PM
BucFan
After getting the opinions of some of the members here, I just ordered the Rugged 3 lug adapter & mount for my 9mm PCC.

Peace of mind indeed.



Sig P229R 9mm - Sig P365 NRA
Sig P320C 9mm - Sig P320 FS .40
August 02, 2023, 03:17 PM
Challer
Except B&T tri lug muzzle devices often won't work with HK spec Tri lug. Some companies like Griffin specifically offer a B&T Tri lug adapter.
August 02, 2023, 08:55 PM
hrcjon
You are going to have to provide a bit of context on that one and some detail. I tried to chase down your note about Griffin offering something to see if it had a hint of the issue, but searching their site for B&T yields nada.
I do however have a lot of experience on B&T products and many suppressors.
If you mean that a 9mm B&T barrel won't accept an HK spec 3lug mount on a suppressor I think that's probably false. It it demonstrably false in my case for at least the dead air, rugged, surefire, silencer co and several other adapters and across dozens of B&T barrels. There are issues across many vendors of the combination trilug/threaded barrel ends and you may have to deal with that, but that's not a B&T specific issue but is that setup HK spec. I had to battle it on my PTR clone and you have to respect the HK spec (usual solution a different thread protector).
If you mean that a B&T suppressor designed for HK tri lug won't fit an HK spec barrel, I think that's demonstrably false as well at least for the currently available US produced B&T suppressors. Those all work fine on an HK MP5 barrel.
If you mean something else I'd have to understand it.
Now it is worth noting that B&T barrels in other calibers are not "HK Spec" because they can't be.
But the B&T .45 barrel works fine with B&T spec 45 tri lug adapters like the rugged one. It isn't and isn't advertised as HK spec.
And the .40 B&T barrel works fine both with a modified (you have to open up the bore) HK spec trilug and also the B&T specific suppressor for that.
I have not tried suppressing the 10mm APC, so no thoughts on that.
So I will look forward to some details on this issue please.


“So in war, the way is to avoid what is strong, and strike at what is weak.”