Is a 30-50 pressure switch EXACTLY the same as a 40-60 pressure switch, other than having a different factory setting?
When installing the pump at our cabin, we wanted a 40-60 switch, but the local supplier only had a 30-50. We reluctantly purchased it, and now regret the pressure. So we were wondering, if the 30-50 is adjusted to 40-60, is it as good as a preset 40-60 one? Thanks.

The pressure switch is a Square D 9013FSG on the switch, or FSG2J21CP on the packaging.

How to adjust water pump pressure, pump cut-on pressure and pump cut-off pressure - private pump and well system do-it-yourself repairs (http://inspectapedia.com/water/Pressure_Switch_Nut_Adjust.php)

Fr Chuck's link is correct. You will need to turn the large, center nut on the switch clockwise to adjust the pressure up. Try two full turns to begin with, then turn the power back on and see the results. If the cut off pressure ends up above 60, then turn the nut CCW to get to 60. Do this adjusting with the power off, then turn the power back on and turn on a faucet to get the pump to cycle so you can see the cut on/cut off points.

That center nut will maintain an interval of about 20# between the cut on/cut off points.