As of yesterday, all P-3 guys going to Randolph must now join the Air Force for a period of 4 years.
In all seriousness, it depends. You can usually expect 6 months worth of training with a variable wait time before you start. Everyone is winged there, then go off to their respective RAGs....either Jax or Tinker. I would tell you selection stats, but that changes on a daily basis.
If you go to Randolph, an average of 6-8 months, with exceptions, is what you can safely bet on.