Subsonic .223 ammo

[dahsma]

I recently picked up a few boxes of .223 55gr subsonic FMJ. I am trying to shoot these through a 20" DI AR platform with a Gemtech G5 can. I can not get the rifle to cycle, have to charge every round. I shortened the buffer spring to the length of the buffer tube and installed an empty carbine buffer (took all the weights out) and it still wont cycle. What do I need to do to get it to cycle? Any information is appreciated.

 

[M25BeastShooter]

Re: Subsonic .223 ammo

Most likely you won't get it cycle as most subsonic loads just don't have the gas power to cycle the bolt. DON'T SHORTEN THE MAIN SPRING!!

Most shooters just cycle the rifle.

 

[BOL556]

Re: Subsonic .223 ammo

I shoot a RRA with a gemtech m4-02 with EBR ammo. You will not get the rifle to cycle no matter what you do. I have heard that the extreme shock subsonic ammo will cycle in a AR however, I havent tried it yet.

 

[dahsma]

Re: Subsonic .223 ammo

Just a dumb question, but will they cycle in a SBR due to the shorter gas system?

 

[M25BeastShooter]

Re: Subsonic .223 ammo

Actually a longer barrel with the longer burn time for the powder may give the gas system more energy to cycle.

I run 12 grains of Hercules 2400 over a 75gr bthp that cycles my AAC M4 on a 16" barrel

 

[dahsma]

Re: Subsonic .223 ammo

Are you using a standard light weight buffer?