An interesting compatibility of parts. Brian B. built this cool SBR. First he started with just a SBR and a barrel extension. Then he got his preferred can. I was a bit confused as to how the MP5SD handguard was attached to the AR upper receiver.

Turns out it is a perfect fit over a samson rail that he is using. It looks good especially with the HK style iron sights.

Looks like a great gun and a fun one too.