How ironic that the only participant willing to do what was necessary lived to be a ripe old age while the rest, who wanted to live to seize power (let’s not romanticize Valkyrie) were promptly executed.
RIP, Herr Leutnant Von Kleist. 
Spy magazine once wryly noted that 98% of Germans alive today are related to the handful of officers who tried to kill Hitler.
If Stauffenberg had put the second bomb in his briefcase, even unprimed, Hitler would have been killed. The blast from the first bomb would have been sufficient to cause the sympathetic detonation of the second.
The Mythbusters test, while interesting, was carried out in a steel container, not a concrete bunker. In a concrete bunker, the force of the blast would have been magnified manyfold.
The running joke back in the day is you could never find a German who fought on the **Western **front in WW2.