12.5 Midlength gasport

[The_Swede]

I’m building a 12.5 upper and for different reasons a chrome-lined midlength Faxxon barrel cut down from 16” to 12.5” is what I’m going to run. Gas port measures 0.075”. Gun will be used 50/50 supressed/unsupressed running M855 or similar duty grade brass cased ammo only. Gasport large enough to run it unsupressed? If not what size would you recommend? I have an adjustable gas block I could use to run different settings for suppressed/unsupressed if necessary. Any thoughts?

[jstone]

I have a 14.5 BCM mid that im going to cut down to 12.5. I plan on leaving the gas port alone, and adjust if needed. Once you get it up and running report back here if you dont mind. I was going to send mine off last week but life decided I needed to spend money on other things. If I finish mine first I will let you know what I find.

[The_Swede]

I have a 14.5 BCM mid that im going to cut down to 12.5. I plan on leaving the gas port alone, and adjust if needed. Once you get it up and running report back here if you dont mind. I was going to send mine off last week but life decided I needed to spend money on other things. If I finish mine first I will let you know what I find.

Sure! FYI it might take me a 2-3 weeks to get everything together and conduct a proper testfire of a few hundred rounds. Looking forward to hearing about your findings aswell.

[prepare]

Triarc and Centurion do 12.5 mid. Don't recall the gas port size though.

[Clint]

The 12.5" MID configuration is best suited to a dedicated suppressed role.

[jstone]

The 12.5" MID configuration is best suited to a dedicated suppressed role.

My plan is for a dedicated suppressed rifle, but I just want to see if it will run without a suppressor. If it won't run without a suppressor I will not open the port until it runs, I may open it slightly if it appears it may run with a minor adjustment.

[vicious_cb]

The 12.5" MID configuration is best suited to a dedicated suppressed role.

This. For both suppressed and unsuppressed get a 12.5" carbine with a 0.069" port.

[kyjd75]

Triarc and Centurion do 12.5 mid. Don't recall the gas port size though.

Looking through my past email conversations with Corrie at Centurion Arms, she indicated that they used a 0.080 port for their 12.5 midlength and 0.067 for their carbine length 12.5.

[w3453l]

Looking through my past email conversations with Corrie at Centurion Arms, she indicated that they used a 0.080 port for their 12.5 midlength and 0.067 for their carbine length 12.5.

They have the gas port sizes listed on their site. As of now it looks like the 12.5 Carbine length uses a 0.064.

https://centurionarms.com/lightweigh...arrel-carbine/

[The_Swede]

I have a 14.5 BCM mid that im going to cut down to 12.5. I plan on leaving the gas port alone, and adjust if needed. Once you get it up and running report back here if you dont mind. I was going to send mine off last week but life decided I needed to spend money on other things. If I finish mine first I will let you know what I find.

Got the last bits mounted today and took it to the range. I have only fired 60 rounds of M855 (so take ut fir what it is) but those ran flawlessly. Gun locks back on an empty magazine on all the mags I tried (Pmag, Lancer and Troy).