I have been searching on here and other forums looking for some sort of definitive answer and haven't been able to find one. I just bought a 20" barrel with a rifle length gas system. I already have a lower built up with a collapsible ACS-L stock and carbine buffer/tube setup. Am I able to use these two together successfully or will I need to change the stock to a rifle length tube and buffer? Or will just a different weight buffer suffice? Any helpful comments appreciated.