From 4000-5500psi and a Scott 2.2 scba bottle is good for 15 yrs in a perfect world.
SCBA cylinder maintenance requirements currently consist of frequent visual inspections to assess, repair, or remove damaged cylinders along with a periodic hydrostatic test of each cylinder (every three years for fiberglass-wrapped and every five years for carbon fiber-wrapped) and replacement of each cylinder 15yrs.
There is a reason the fire departments rotate their inventory and one should be very careful of what they are buying.
Dive shops refill scuba bottles in cold water to increase pressure in the bottle for the diver, not sure if this method is used when refilling scba bottles.
Something to consider or look for when refilling.