Okay, so I put a 20kΩ resistor between a 5V supply and the base of a 2N2222 with the collector connected directly to the 5V rail and emitter to ground. What I'd expect is that, roughly, 220μA (i.e. (5V-0.6V)/20kΩ) goes into the base and less than 22mA (i.e. 220μA*100) comes out of the emitter. This isn't what happens at all. I tend to get over 45mA coming out of the emitter.
First, I thought it was my resistor precision. I checked and the actual resistor value is 20.2kΩ (0.1Ω resolution).
I thought it might be the specific transistor but I tried two other 2N2222's. The first was from Mouser and the second two from China. All give roughly the same result.
I then thought maybe it was because I'm using a noisy buck converter. I switched to a linear regulator that gives 4.999V stable for several volts over the +1.6V.
I checked the circuit in CircuitLab using the exact values of my configuration and it gives me what you'd expect: 215.0μA in to the base and 23.17mA out of the emitter.
What's going on? Is this happening because I have no load? Is it because I'm doing this on a breadbord? Do I need capacative decoupling/bypass? Or do I seriously have 3 broken/fake transistors where one of them came from Mouser? If so, why are they all giving the same output?