Gundrills today are used in a wide range of ferrous and non-ferrous materials, machine tools, and hole depths. Because of this variety, it is difficult to specify the exact speeds, feeds, tool geometries, and coatings that should be applied for any given application, and some amount of fine-tuning should be expected.

Here are some general recommendations when troubleshooting gundrilling operations. Only one adjustment should be made at a time, documenting the results as you go.