Gun drilling process is used to produce deep and straight holes. This process is very specialised as compared to the conventional twist drilling process. The standard gun drill tool geometry has a single effective cutting edge. Unlike the twist drill the gun drill cuts through the metal eccentrically and once inside the component the tool self-pilots itself. The hole is further burnished due to the guide pads which finally results in a precise round hole with maintained straightness. The Coolant enters the tool through the coolant through hole and the chips are gushed out through the V shaped profile on the gun drill. Gun Drilling is effective from Ø1 to Ø30, but if you wish to go higher BTA drilling becomes more effective than gun drilling.