All the above. If you look at the case it will liekly have the letters "NT" on it, for "Non-toxic". It means the primer used DDNT instead of lead styphnate, which is a more violent explosive and if the hole isn't made bigger it backs itself out of the pocket an can pop itself before the case is pushed back over it to surround and protect it.
The standard primer flash hole is 0.080"±0.010", so, 0.070" to 0.090". That means a #50 drill should fit through, if snuggly, while a #42 drill bit should not fit. 5/64" is about 0.0781", so slightly smaller than average. Keep in mind that when you mic standard drill bits it's not uncommon for them to be a couple or three thousandths under their nominal size. There's a table of drill sizes,
here.
The 1/8" hole is, as already explained, used for NT, for wax bullet shooting, and is also used by the military for their G11 formulation high temperature primers. I've never heard of a .45 Auto case having a problem with the substitution of a standard primer in these. It's a low pressure round anyway.