I am ready to swap out my stock MB for a Surefire SOCOM FH and Warden combo.
I also got a FBA washer and peel washers for the indexing.
In the process of the swap I noticed removing the stock MB was just simple.
Two combo wrenches, one on locknut and one on MB, with the twisting effort mostly on MB.
It popped loosed with mild effort.
As I'm looking at the assembly to go on I realize the FBA washer is a nice small piece that helps spread the load across the shoulder profile on the barrel.
I also notice the stock lock nut has the same qualities.
The FBA washer measures .112" long. The threaded portion of the stock lock nut measures .135" long.
What's the difference?
The FBA has a full 360 degree bearing load to support and MB/FH device torqued against it.
The stock lock nut has the same, if not more because there are at least two full turns of threads engaged, (but, area of contact on threads are smaller due to thread tolerances).
Without getting into true measurements, I would say that both are great ways to support the barrel end devices, especially when only torqued to 25 ft. lbs. and using loctite.
So at this point it comes to cosmetics and ease of assembly.
The FBA washer will most likely need peel washers.
(Note - This actually depends on how the piece is machined. Most CNC machines will start the thread at the same place consistently according the spindle. But production of the part may not machine a indexable profile at the same operation of the threads being cut.)
My Surefire FH does not need peel washers to index perfectly using the FBA washer.
FBA washer, peel washers and Indexable device.
Stock lock nut and Indexable device. (Note - peel washers will not be needed since the lock nut would be used to properly index your device.)
Here are images of my research.
With FBA and FH device, nice clean install because I don't need peel washers.
Stock lock nut and FH device, also clean install but a little chunky with the nut being fatter than the end of the FH.
Anyway, it's just information to digest.