No! Bought 2 and neither had the crush washer!
SIG SAUER does not provide the length of their QD Taper-Lok Muzzle Brake Mount. I would recommend contacting them directly for more information.
Sig Sauer does not provide information or testing on how the concussion is when using the SIG SAUER QD Taper-Lok Muzzle Brake Mount without a suppressor.
Sig doesn't make any mention of cross compatibility of brake or flash hider components between devices. I would advise contacting them directly by calling Customer Service at 603-610-3000 option 1 Monday-Friday, 8:30am-5:00pm EST.
These muzzle brakes are intended for use in Sig Sauer SRD556-QD and the SRD556Ti-QD silencers. They will not fit inside the SRD762 or SRD338 series silencers.
This is just the muzzle brake/suppressor QD mount. The thread pitch you want will depend on the caliber and thread pitch of the rifle you're putting the muzzle brake/QD mount on. If the caliber is 5.56/.223, it's most likely 1/2x28. If it's a 7.62/.308 caliber, it's likely a 5/8x24 thread pitch and would need a different muzzle device.
These muzzle brakes are intended for use in Sig Sauer SRD556-QD and the SRD556Ti-QD silencers. They will not fit inside the SRD762 or SRD338 series silencers.