What about hard shotgun barrel one? :'(

A kill was indeed possible. The first two replays below show it done with 36 hp and 22 hp of self-damage; the third replay is the best, with 0 self-damage and a much better hide:

you know when chutes last less than a quarter second when you are really dealing with pro moves xd

I don't think you understand the concept here. Those shotgun kill replays are fully-tool-assisted from 3:27 onward, showing something that was theoretically possible but quite unlikely to get with unassisted play. There's no point in doing the parachuting unassisted (even though it was an easy chute climb) when the shotgun shots are going to be fully tool-assisted anyway.

The number after the opening { brace is the number of re-records.

For an explanation of what "tool-assisted" means, perhaps you can follow the link named "What does Tool Assisted mean?" in https://tasvideos.org/WelcomeToTASVideos.