I can see Biden being that low and self centered.
There is a streak of the Frustrated Dictator in him. He shows an urge to force others to do his bidding. Notice how he likes to fondle women, typically during a public awards ceremony, where the average person will tolerate a lot of unusual behavior in a formal setting.
That’s probably why he and Obama got along so well, takes one to know one.
Here is the story about switchblades and armor piercing bullets where the Biden incident is recounted:
http://gunwatch.blogspot.com/2015/02/556-ammunition-and-switchblade-knives.html