Quad rail

[arm_usa]

https://centurionarms.com/centurion-arms-quad-for-7-62/centurion-arms-8-7in-free-float-quad-rail-7-62/
 

Just bought this one in hopes it completes me. Going on my 10.5” 308 SBR. Hope to have a picture up next week and a small review. Fingers crossed it will bridge the gap between my heart and a DD Lite rail. 
 

this is a birthday purchase. A $400 part for me nowadays doesn’t happen much ever anymore. 
 

 

Edited June 2 by arm_usa

[98Z5V]

7 hours ago, arm_usa said:

Fingers crossed it will bridge the gap between my heart and a DD Lite rail. 

Truth, brother.  I have one of the last remaining DD Lite rails we've ever seen here, but I also have one of these rails as well - it's quality, and well worth the investment.  Fear not.  

[arm_usa]

Shes a beaut Clark. It’s close enough for me so I’m happy. I need to replace my barrel at this time so when $$$ comes in I’d like to show off the SBR quad setup. 
 

it’s simple enough and straight forward to install. Just pricey. 

[98Z5V]

On 6/15/2026 at 11:35 AM, arm_usa said:

Shes a beaut Clark. It’s close enough for me so I’m happy. I need to replace my barrel at this time so when $$$ comes in I’d like to show off the SBR quad setup. 
 

it’s simple enough and straight forward to install. Just pricey. 

You GOTTA be kidding me man!!!   Put some pics up!!!  

[arm_usa]

On 6/18/2026 at 12:03 AM, 98Z5V said:

You GOTTA be kidding me man!!!   Put some pics up!!!  

So…just now installed today. It was very tight. Almost too tight. I don’t ever want to disassemble this thing. The rail gives me just enough clearance to adjust the rifle speed gas block. Sad thing is,it’s set in the most closed setting out of 12 positions and it cycles decent. Ejection is 2-3o’clock. Apparently you need to buy different plungers to have a different range of settings. 
 

id like 3-4 o’clock ejection so i need to get a kit from them to close off the port more. The KAK 10.5 carbine gas port was .071”. My cut down BA 12.5” barrel was I think slightly smaller which was enough to cycle on any setting. I still have the BA I cut to 10.5” from 12.5” atleast but I wanted to try this KAK barrel. 
 

I like the rails look very much. This size is very handy but I gotta ask an opinion from everyone. Is this 10.5” 308 worthy of a 1-6 like it has or should I save it for another setup? Should I go red dot and x3 magnifier instead? Still bulky either way or just do a red dot? This build was supposed to be an upscaled mk18. Just curious in what everyone thinks. 
 

this is a fun gun. It might see occasional 300+ yard shots on steel. I might go to TX to visit a good friend and hog hunt. Hope you guys like how the rail turned out. 

[Rsquared]

She looks pretty sexy. Definitely gets the R2 seal of approval. But I also have a thing for SBR's.

I'd say that the 1x6 is fine for it. It gives you the flexibility for being up close, or stepping out a decent distance.

I run an Elcan DR Spectre on my AR-10 SBR. It can switch from 1x to 4x by flicking a selector on the side of it. 

Everybody has their own preferences anyway. So I say run whatever you feel comfortable with. 

[Albroswift]

I like the riflespeed AGB. Only thing I'm curious about, the way they measure the tube did you have to buy/ mount the AGB, Then take the measurement, then order the straight tube? 

[arm_usa]

2 hours ago, Albroswift said:

I like the riflespeed AGB. Only thing I'm curious about, the way they measure the tube did you have to buy/ mount the AGB, Then take the measurement, then order the straight tube? 

I actually just bought a carbine length straight gas tube. I think I got it from them. So it’s a true DPMS/AR15 gas system straight tube. Works out great so far. It’s easy to switch where it’s at but I will never switch it after I find the seeet spot. Which is closed as much as possible lol. I will 99% never run this unsuppressed cause the 10.5 with a brake just hurts to shoot 😕