HK 3 Lug Connection

[dek]

 If you have both 1/2x28 and 13x1 available is one preferable to the other? I like the idea of the HK 13x1 - LH thread and locks with retaining clip. No need for loctite.

[OpusXJ]

The retaining clip doesn't always line up on the 18x1 mounts. I'd use a 1/2"-28 mount and some Rocksett.

[Bill_J]

With 3 lug its easy to never have to worry..... Always turn clock wise.  That way every time you take the suppressor on or off, you are tightening the mount to the barrel.

But I still put a drop of rocksett on them.

[OnlyHereForEE]

Doesn’t matter. I prefer 1/2x28
Use
Rocksett and you’re good to go

[cocowheats]

The retaining clip doesn't always line up on the 18x1 mounts. I'd use a 1/2"-28 mount and some Rocksett.

This.

I used an HK Parts 18x1 and then cut/threaded the barrel for 1/2x28 and now use a 3lug in 1/2x28.