Fixed barrel spacer question

[slacker1972]

I just got my Rugged Obsidian 45 and I also bought the 9mm adapter and a 9mm fixed barrel adapter for my Sub 2K.
I see that rugged also sells a fixed barrel spacer.
My question is do I need a fixed barrel spacer or just the fixed barrel adapter for my carbine?
Thanks

 

[Allsmiles]

If the barrel doesn't move (like AR9 and most rifles) then you need the piston and spacer and no spring. If the barrel moves (like most pistols) then you need the piston and spring. The fixed barrel spacer keep the suppressor from pounding the rifle and damaging either the rifle or heaven forbid the suppressor. I don't think the Sub2k barrel moves (don't know too much about them); so you will most likely need the spacer.

 

[slacker1972]

If the barrel doesn't move (like AR9 and most rifles) then you need the piston and spacer and no spring. If the barrel moves (like most pistols) then you need the piston and spring. The fixed barrel spacer keep the suppressor from pounding the rifle and damaging either the rifle or heaven forbid the suppressor. I don't think the Sub2k barrel moves (don't know too much about them); so you will most likely need the spacer.

OK thanks, the Sub 2K is a fixed barrel so I guess I will need to get the spacer too.

 

[Allsmiles]

Then you will need one. Good thing is they are usually cheap. Also, some suppressors leave a little gap when they at in to remind you. Best check your thread pitch and see if it is 1/2x28 or 1/2x36 to make sure you have the right piston. Stock up on subsonic ammo as it is a lot quieter.

 

[C'mon man!]

I'm skeptical on the info in this thread. OP, you said you purchased the 9mm adapter and a 9mm fixed barrel adapter, by 9mm adaptor, do you mean 9mm piston? And, 9mm fixed barrel adapter, do you mean the fixed mount, like shown below?

 

[C'mon man!]

If you are using the fixed mount, the spacer is not needed.

 

[HydroAuto]

There are two things being discussed here. Fixed mounts and spacers to convert a piston assembly into a fixed mount.

If you have a piston/cap/spring assembly for tilting barrel applications, you can use the spacer to adapt the piston/cap for use on a fixed barrel firearm.

If you have a fixed mount, you can use that on a fixed barrel firearm alone.

What is going to drive your decision is what the threads on your barrels are. For instance I have an Obsidian 45. I also have a 1911 that is threaded .578-28. So I have a .578-28 piston/spring/cap assembly for using the Obsidian on the 1911. However, I also have an AR in .45ACP with a barrel that is threaded 5/8-24. So for the AR, since it is a fixed barrel, I use a 5/8-24 fixed mount. However, if the AR was threaded .578-28, I would have gotten a fixed barrel spacer instead, and swap it in place of the spring. I also have a .45 Colt lever gun that I want to suppress, and due to the barrel thickness it will need to be threaded .578-28... so my options are going to be either purchase a spacer for $59, or a .578-28 fixed mount for $80

 

[slacker1972]

I'm skeptical on the info in this thread. OP, you said you purchased the 9mm adapter and a 9mm fixed barrel adapter, by 9mm adaptor, do you mean 9mm piston? And, 9mm fixed barrel adapter, do you mean the fixed mount, like shown below?

Yes I bought a 9mm adapter with a piston for my Glock 19 and then I bought the 9mm fixed barrel adapter pictured above for my Sub2k.