When putting on a suppressor mount with the Galil ACE GEN II Rifle – 7.62x39mm I was wondering about how you should mount it.

The firearm comes with a jam nut that's behind the stock OEM flash hider and I'm wondering if for an AAC 51T muzzle device you should be removing the jam nut and just torquing the device down to the end of the barrel, torquing it to where the jam nut is currently, or like if you backoff the jam nut further down first, screw on the muzzel device and then tighten thigs up by raising the jam nut to the end of the barrel up against your muzzle device.

What's the proper method to set up putting on a muzzle device on these? In the photo below you can see an AAC suppressor mount like I'm trying to affix and the jam nut under it.

On my ACEs, I'm using griffin muzzle devices.  What I did was back off the jamb nut all the way back.  Then unscrew the factory brake.  Twist on the griffin muzzle device all the way, but then back it off a little bit so its timed correctly.  Then run the jamb nut back up into the muzzle device to lock it into place.  All mine checked out fine with an alignment rod and haven't had any issues with them coming loose or unaligned.

This assumes that the back of your muzzle device is machined square to the bore to a reasonable tolerance and that it was manufactured in a way that you can index it off that back face.

I went with a Huxwrx HX-QD 556 for my first rifle can. Used their flash hider. Once I got the factory A2-ish flash hider off I backed the jam nut all the way to the barrel shoulder, backed it off a half rotation, threaded the new flash hider down to the jam nut, and then tightened them together.

An alignment rod showed very slight off center. Several live rounds through the can and no end cap strikes.

You have to use the jam nut because the threads are far too long. You'll bottom out your suppressor mount

I got an aftermarket jam not that was much smaller than the one that came with the ACE.  It allowed the muzzle device to grab onto more threading and ultimately makes the gun shorter.  Using the factory jam nut took too much of the available threading.

On Friday I had the Dead Air keymo brake installed on my 13" Gen 2.
The gunsmith was able to time it with the shims against the jam nut and I was pleasantly surprised that everything was concentric.

I rethreaded a 14x1 LH OSS AKM flash hider for 5/8"-24. The 14x1 OSS brakes and flash hiders have an internal face that allows the flash hider to index off the muzzle face. The jam nut is decorative now.