I'm not a gas gun expert. I've shot KAC for years at work and I'm aware the two most popular patterns are DPMS and Armalite but my personal gun is KAC pattern. I know LaRue, LMT, etc use KAC pattern but I'm not sure what that means besides upper/lower and mag compatibility. The reason I'm asking is that I won a Columbia River Arms barrel cert at the last match and I'm wanting to use it to build a 6.5 Creed upper but they are DPMS pattern. Does anyone know if the two are compatible? For example, if you order a LaRue Ultimate Upper kit it asks DPMS or KAC? No difference is mentioned in regard to barrel but they may not all because they know what upper pattern you specified. Anyone in the know?

So, I don’t ‘know’ because I’ve not built on all the platforms....just DPMS (wish there was a standard spec), but (I was wrong on differences)....seems the barrel threading and extensions are different....1/16 tpi vs 1/32 tpi (kac)