Warning

 

Close
Confirm Action

Are you sure you wish to do this?

Cancel Confirm
AR15.COM
Armory Sponsor
8/1/2017 4:02:24 PM EDT
I'm sending my MPX barrel to be chopped and re-threaded by ADCO.  I plan to run my SF Ryder 9 via direct thread until my Revolution 9 gets out of NFA jail.  Once I get the Rev9 I plan on doing a 3-lug set up.

Which leads to my question.  The Griffin Armament 3-lug adaptor is set up for 0.625 threads.  IIRC standard pistol thread depth is 0.40.  Any issues with attaching the 0.625 3-lug adaptor to a 0.40 barrel?  I assume the best approach is to thread the barrel to 0.625 and run a spacer on the SF Ryder 9.  Would love input from the hive.

Edit: for proper GA thread length
8/1/2017 8:25:15 PM EDT
[#1]
I'm pretty sure Griffin is talking about the length of the threads from the first thread to the last one. Because 0.650" is bigger than 5/8"(.625").
8/1/2017 8:32:43 PM EDT
[#2]
Sorry wrote the wrong number for GA 3-lug adaptor thread length. It is .625.  Link to adaptor.
8/1/2017 9:40:41 PM EDT
[#3]
If the Ryder can index off the muzzle, have it threaded to 0.625" and don't worry about a spacer.

If the Ryder can only index on the shoulder, thread it to 0.4". The only downside with that is that you may get carbon/lead fouling on the on the last .225" of threads on the 3-lug adapter which would make it difficult to thread onto something with 0.6" threads should you try to reuse the adapter later on.
Armory Sponsor