Well I currently don't have any surpurlative GB in use or any other brands that do. I have bought 2 before that we're just total failures. With a very short barrel (under 8') and a 308 based cartridge the GB can't vent it fast enough for the volume of gas there is? Some can be expuled with the use of certain types of chargehandles (out of the face).Not necessarily. The excess gas is bleed out the front of the adjustable gas block with some designs. Superlative Arms gas blacks are some of the most popular and recommended. They are my go to. Simply and easily adjust the flow to coincide with the type of ammo you are using if need be.