I run the Stern adapter for Glock magazines… mainly because I’m issued a Glock 19. I have another SBRed lower that takes Colt magazines. Between the two… I prefer the Colt version. Easy to pull out but keeps the controls identical to a 5.56mm gun.

If you decide on Colt, follow this to a T.

https://blowback9.wordpress.com/2022...t-mag-adapter/

My current setup with Glock magazines has a 6” barrel and my Dead Air Odessa under the handguard. I have a Angstadt Vanquish 10.5” integral suppressor waiting on me to do the Form 4. I wanted to get the Odessa freed up for other use, especially since I only run that setup suppressed.

My Colt setup is similar to the DOE gun. Mainly just a fun gun, but I’m considering to pick up a 10.5” H&R upper as a spare for when I want a little extra length.

Optimal length… I’ve heard 7” to 8” is best for 9mm when you consider burn rate, accuracy and maneuverability. I know some that like under 6” for use with suppressors… to me, why not just get a Glock? I have a 16” Beretta CX4, which is a great shooting carbine. To me, SBR 9mm AR is funner that a 16”… and what I prefer.