9 millimeter 

See 9 mm.

9 millimeter by Fangsta March 18, 2003

9 millimeter solution 

The use of a firearm, such as a 9mm pistol, to solve major people problems via homicide or suicide.

The retired cop choose the 9 millimeter solution, when his doctors told him he had incurable, painful cancer.

9 millimeter solution by I, Wreckerrr July 23, 2019