With regard to what buffers are come in Colt Commandos, I have seen standard, H, and H2 in USG 11.5" Colts. Who knows in what configuration they came from the factory...??
The US military now supplies(new stocks) all H2 buffers for the m4 series. I have seen this in US Army & USN repair shops.
Of note, sometimes a H2 buffer will impead function in extreme cold at extreme altitude. Perhaps a function of the above & new weapon with tight gas port. Probably only a handful of people in some units have experienced this.
