Anyone have a problem with a Sig QD mount not attaching to a Ruger American Ranch Rifle in .300 BO?

Not open for further replies.


Oct 24, 2015
Realized this was placed under scopes and should be in rifles where it maybe seen more.

I have a Sig SRD762Ti with QD. My friend tried to attach it to my Ruger American Ranch Rifle in .300 Blackout and said that the mount goes over the threads and only catches about 2-3 of them. He said he thinks that it needs to be "downturned" and have threads added. I can't think that that is the problem, it's also expensive.

Maybe I need a different mount. But it comes with a QD muzzle device which is 5/8”-24tp and the rifle is also threaded 5/8”-24tp, so it should be fine.

My friend said that he would like to see 4-6 full turns onto the threads which is 1/2" inch while he's only seeing less than 2 full turns and only 1/8" of an inch right now. He said it's solid but it could potentially come loose and cause issues.

I don't know if I need a different mount or what but I watched the video by by Sig showing the QD being screwed onto what appears to be a Remington with the same length of threads and it is spun like 5-6 times with a gun that has a 90' angle thread, not a tapered thread, so that shouldn't be the problem.

Anyone have a problem with a Sig QD mount not attaching to a Ruger American Ranch Rifle in .300 BO?
From the video you posted, the brake assembly consists of three pieces - a part that threads on the muzzle first, then a crush washer, then the actual brake. I the photos you posted, it looks like you are trying to attach is as a unit. Have you tried disassembling the brake assembly and following the instructions in the video (only installing the forward part of the assemble after the rear part is tightened against the shoulder)?

If that doesn't work, I'd follow the final part of the video instructions, and contact Sig :). They can supply the specs for compatible threads.
Yes. Didn't work. I have contacted Sig. They are looking into it.

My friend said the adapter is hitting the shoulder, so basically not enough threads for that particular adapter. I hate how the threads in the adapter start so deep, not right on the outside of the adapter. I haven't seen any other adapter that would work, hopefully there is one out there. I'd rather get a different adapter or modify the adapter than permanently alter the rifle barrel.
Update: Resolved

Apparently there are different adapters for different rifles. The suppressor comes with the adapter that fits the Sig line of weapons, no surprise there. I wish they would have put this on their website, that different rifles require different adapters. The new adapter I received definitely has a lot more threads in it and they start far earlier making the threads start far closer to the end of the adapter. I'm happy that I didn't have to do anything drastic like downturn the barrel or buy a custom adapter.

I know that Sig has been knocked in the past for having some horrible customer service but I've got to say that I was treated great. Their employee went out of his way to take care of me.
Last edited:
Not open for further replies.