Double A - good eye you have there. You too might want to get one of these bad boyz and try your hand at cumpetitvly shooting. That is a custom one-off 3 stage recoil designed for me by the Navy Seals armorer. The material it is constructed of is classified.

low temp - you too are one of the sharper knives in the drawer! I have experimented with several different porting systems, but after chronoing each I found I had lost a bit of velocity and I will not tolerate that. I did fit a BOSS type system to a barrel as an experiment but the muzzle blast kept blowing it off. I even tried welding it on but I believe that the extreme muzzle flash was vaporizing the weld and it would then blow off on the very next shot.

[:-]