In choked flow, you don’t need a very high pressure ratio to go sonic. You only need P_exit/P_reservoir <= 0.582. That is, the pressure of the reservoir (the bottle in this case) only needs to be 1.72 times greater than the exit pressure (ambient).
[0] https://en.m.wikipedia.org/wiki/Choked_flow
If you've ever used a compressed air gun from a compressor or at a tire fill station, it's also very likely choked flow, sonic exit speed.
In choked flow, you don’t need a very high pressure ratio to go sonic. You only need P_exit/P_reservoir <= 0.582. That is, the pressure of the reservoir (the bottle in this case) only needs to be 1.72 times greater than the exit pressure (ambient).
[0] https://en.m.wikipedia.org/wiki/Choked_flow