Changing string gauge
One of the many common questions we get is about changing string gauge on an instrument. Typically, it's about putting a heavier gauged set on something that currently has light gauged strings.
When changing string gauges there are two important points to remember:
1. The slots that hold the strings in the nut are cut to specific sizes to accommodate the gauge of strings being used. A slot that's too big will allow the string to vibrate (buzz) within the slot. While a slot that's too small will bind the string and cause tuning problems.
2. You will also need to re-intonate your bridge saddles. Because of the different size wire used, changing string gauges also means you will need to readjust the placement/intonation of your bridge saddles. This can be done with a good tuner and the proper tools.
Both of these tasks can be done by yourself or a qualified repair person.