Firearm

The Machine gun was a weapon created on Earth. The weapon fires projectiles (bullets) at a high, automatic rate. They are more widely available than Pistols.

This type of weapon was generaaly inneffective against such alien races including the Daleks and the Cybermen, but are effective to kill Ood and pierce Sontaran armour, if the bullets weren't influenced by the cordolaine. Machines were still widely used by the people of Earth beyond the 21st century. Examples of machine guns being used

They were used to shoot and subdue the Ood both on Sanctury base 6 and on the Ood Sphere.
The army and UNIT used them to repel the Sontarans, Daleks and the Cybermen.
Gwen Cooper and Ianto Jones used machine guns to combat the Dalek in the Torchwood HUB
The Hath and humans on Messaline carried heavy duty blaster rifles which were used to fight the war over who took control of the planet.
When the Dalek escaped in Utah the security force attempted to subdue it with machine guns.
On the Gamestations Baastic bullet guns were used to try and stop the Daleks from invading.
The masters private Swat Teams fired on the Doctor with machine guns.
Captain Jack led a squad of men to shoot the Toclafane with machine guns.
The preachers used a number of automatic weapons to fight the Cybermen.
Mounted machine guns were used to shoot the Scarecrow Drones when they attacked Farringham school.
On Mallcisairo the guards repelled the Futrekind with machine guns.
Miss Fosters guards were armed with machine guns.