SIGforum
3-lug adapter for my MPX

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http://sigforum.com/eve/forums/a/tpc/f/380105858/m/9290062444

July 11, 2018, 01:58 PM
soggy_spinout
3-lug adapter for my MPX
Any surprises in store or things that I overlooked if I decide to go this way?

I've been looking hard at the Griffin Optimus system and one of the attachment configurations that it can accommodate is for 3-lug, which seems to be the "simplest"/cleanest way to use that suppressor on a MPX with its standard thread pitch.

Near as I can tell their regular (Griffin) suppressor-ready taper mount muzzle devices would require a 13.5 x 1 LH to 1/2 x 28 adapter before I can use their compatible muzzle device; to me that's extending things a bit too far beyond the end of my MPX's handguard.

Meanwhile I'd just put on a 3-lug flash hider while I'm waiting for my paperwork to be approved...
July 11, 2018, 02:25 PM
dusty3030
I responded but misunderstood you the first time.

Yes, I would got with Griffin 13.5x1LH 3 lug adapter and Griffin 3 lug option on the can for the MPX. That will be the shortest / easiest for the 9mm.
July 11, 2018, 03:16 PM
CandyMan.45
You would use one of these: https://www.griffinarmament.co...g-Adapters-p/93l.htm
July 11, 2018, 09:38 PM
Rangerone
I have put the Griffin Armament 3-lug adapter on my MPX and it works with my 3-lug mount for the Omega45K and the TI-RANT45 with the Triad mount.

I have a couple of different 3-lug flash hider that I can attach when I don't have the suppressor attached (but I have the can on the MPX almost all the time).

Use Rocksett on the threads before attaching the 3-lug adapter, let it set and then you are good to go and not have to worry about the can backing off (one of the benefits of the 3-lug system).
July 12, 2018, 08:48 AM
soggy_spinout
Appreciate the advice from all. Thanks.
July 21, 2018, 09:09 PM
Shackelford
Because of the outer diameter of he LH heads, the three lugs are much farther forward, past themuzzle, unlike with a 1/2x28 muzzle device. If you care about overall length, it is a little ungainly.

I cut my barrel to 6.5" and had it threaded 1/2x28. These days, there are some aftermarket barrels out there, and you can get 6,5" with the lugs, so I'd probably go that route, and leave my factory barrel unmolested.
July 22, 2018, 03:07 PM
Mike748
quote:
Originally posted by Shackelford:
Because of the outer diameter of he LH heads, the three lugs are much farther forward, past themuzzle, unlike with a 1/2x28 muzzle device. If you care about overall length, it is a little ungainly.

I cut my barrel to 6.5" and had it threaded 1/2x28. These days, there are some aftermarket barrels out there, and you can get 6,5" with the lugs, so I'd probably go that route, and leave my factory barrel unmolested.


I bought a 6” from ILWT for this purpose. It works very well.
July 26, 2018, 01:40 PM
soggy_spinout
quote:
Originally posted by Shackelford:
Because of the outer diameter of he LH heads, the three lugs are much farther forward, past themuzzle, unlike with a 1/2x28 muzzle device. If you care about overall length, it is a little ungainly.

I cut my barrel to 6.5" and had it threaded 1/2x28. These days, there are some aftermarket barrels out there, and you can get 6,5" with the lugs, so I'd probably go that route, and leave my factory barrel unmolested.

Good to know about the availability of aftermarket barrels; I may go that route if I decide a tighter, more continuous look is more my style. Wink

I did notice the added length after I installed the Griffin adapter on the factory 8" barrel. It's a little more far forward but until I get my Optimus approved and on the gun I really don't have any concerns. Plus even with the adapter 'out there', it still looks better than the birdcage to me.

I never took to the look of the factory flash hider, as if it's trying to be a mini 5.56 gun. And as I soaked the muzzle to dissolve the Rocksett that SIG supposedly uses (roughly 6 hours starting with hot tap water), the darn birdcage rusted a lot faster and worse than I would have expected. No rust with the barrel however, so I'm thankful of that.

Other than discovering that I didn't have a crowfoot wrench in the right size--damn those things are expensive when buying them individually--the adapter went on without any real issue though my Wheeler barrel block was having a tougher than normal time keeping the barrel from twisting within the block. Tightened it to around 35 ft/lbs per Griffin's guidance, and it's now supposedly GTG. Just need the Optimus and I'm all set.
August 23, 2018, 08:05 AM
Bluecobra
I initially put the Griffin adapter on my stock barrel but didn't like the extra length. BTW, my factory birdcage came off with a wrench. No soaking was needed.

Anyway, I ended up with a 4-1/2 barrel that has the 3 lug machined into it, then put my supressor on that. Yes, the barrel ends before the keymod does but I doubt I will shoot it without the suppressor. I did move the hand guard at the end of the keymod back a hole or two.
August 23, 2018, 12:29 PM
PorterN
quote:
Originally posted by Bluecobra:
Anyway, I ended up with a 4-1/2 barrel that has the 3 lug machined into it, then put my supressor on that. Yes, the barrel ends before the keymod does but I doubt I will shoot it without the suppressor.


Are you still using the 8" handguard?
I bought one of these 4" carbon fiber guards from lancer, and love it.



____________________________
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September 22, 2018, 08:25 PM
Freq18Hz
I had an issue shooting 300 blk w/ a gemtech 9mm can rated for 300 subs...huge accuracy issues.

The same can works great though on a 9mm b&t w/ a three lug.

This is probably due to 300 blk but I do notice that the griffin 3 lug has more wobble.

If you want to try it, my griffin 3 lug is sitting here and needs a home.


-Freq
September 24, 2018, 01:30 AM
soggy_spinout
quote:
Originally posted by Freq18Hz:
I had an issue shooting 300 blk w/ a gemtech 9mm can rated for 300 subs...huge accuracy issues.

The same can works great though on a 9mm b&t w/ a three lug.

This is probably due to 300 blk but I do notice that the griffin 3 lug has more wobble.

If you want to try it, my griffin 3 lug is sitting here and needs a home.


-Freq

Thanks for the offer but I already picked up the Griffin 3-lug muzzle adapter and have it installed on my MPX. I haven't picked up the (supposedly) matching Griffin 3-lug coupling that attaches to the Optimus can (also Griffin) that I'm patiently waiting approval for. The wobble issue seems to be a common theme with that 3-lug barrel attachment when other makes of cans are used. I haven't heard much bad (or good for that matter) when the silencer setup is 100% Griffin Armament. I'm hoping that their fit will be good and reasonably secure and won't create any adverse effects.
September 24, 2018, 07:49 AM
Freq18Hz
Yeah...I have no issue w/ 9mm through the gemtech can I have, just 220gr .300blk.

When you mount the can, just make sure that there is significant spring tension required to fit it on to the lugs, and that when it 'locks', it fits secure with minimal/no side to side movement if you try to rotate the can. If you have a bit of play and want to be extra safe, use an alignment rod and see if you can wobble the can with a bit of force from your hand and still maintain alignment.

-Freq