I am looking to build out a couple of uppers. One in 5.56 and the other in 300 blackout, both with short (8"-10") barrels.Both will be ran suppressed and unsuppressed but not FA. I will use both subsonic and supersonic ammo on the 300. Unfortunately I drug my feet on getting the barrels and now they are like hens teeth. I found a Noveske 5.56 barrel 8.5 with no switch block. Is a switch block neccessary on a barrel this short or is there any discernable difference? Thanks in advance for any advice.