I usually just start with the smallest drill bit that I have and work up from there... I run natural gas for my burner though, so the pressure is a bit less... If I'm using the burner to heat up a cast iron grill plate for blackening some steaks when I'm away from home though, I use LPG with it... Unregulated LPG, so I have to be very careful with how much I open the LPG tank's valve, otherwise, I can get a 6 ft column of flame...