An interpretation of the The Beatles "Happiness is a Warm Gun" from their 1968 double vinyl album "The Beatles"

No, the songs not about "shooting up" meaning injecting illegal drugs like heroin or cocaine Rather, like most songs of the Britsh Invasion it's another of their observations of American people and the meaning of the song is that in America you can't endeavor for happiness if you need a gun and so the pursuit of happiness is displaced by instrictive defensiveness caused by the fact that in America, unlike England, firearms are legal and prevelant More importantly the  continuation of the Beatles charter to follow Bill Shepherd's (Billy Shears/Sgt Pepper's) work in study, imitating and continuing American music Additionally in case you're still confused, Bill Shepherd's a real person with a career as an important force in music from the 1940's until the present day Billy Shears and Sgt Pepper are ficticious references to the real Bill Shepherd "Shears" because shepherds herd sheep and sheep are sheared "Sgt Pepper" because of his group the Pepperpots