Quote Originally Posted by gunf1ghter View Post
I called HK parts and they say that their 3 lug mounts are not made by griffin.

However, they acknowledged that they have had users have these issues who own the Rugged Obsidian this year and said there could be enough variation in the 3-lug adapter length to cause the issue.

They have offered to send another unit to me after I send mine back to test out and see if I have more success with it.
This is an old thread and hopefully you have sorted it out. But wanted to add that Tri Lug adapters (the parts that go onto your barrel) are not all made the same. As far as I can tell the ones from Hansohn Brothers have the 0.300" wide lugs that seem to fit the Silencer Co, Rugged, and Griffin Tri-Lug mounts (the part that goes into the suppressor).

But I was told by Resilient that their Tri-Lug mount for Bravo threaded suppressors would not accept the Hansohn Brothers adapter because the lugs are too wide. There is another tri-lug spec floating around where the lugs are like 0.250" wide or something like that. Resilient said they are producing a mount that can accept the 0.300"+ wide lugs later on.

The part of the tri-lug barrel adapter that slips into the mount insert should be 0.590" as most of the mount inserts have an ID of 0.593" (Rugged, Griffin) or 0.5945" (SiCo)

I found the Griffin tri-lug mount to be the most stable with the least slop/lateral wobble.