The full song which I learnt when I lived in India as a child went like this:

Oh I've only 5 bullets in my old six shooter because I had to say goodbye to Mona
And her old saddle's lying where the west wind's blowing in the lonely state of Arizona


We had travelled together far, in fair and stormy weather, and for many years I'd been her owner
Now I've only 5 bullets in my old six shooter because I had to say goodbye to Mona


When she stumbled and fell at the roundup I knew we had to part
And the look in her eyes that she gave me well it nearly brought my heart


Now I'm the loneliest cow puncher on the whole darn prairie from Nevada down to Arizona
and I've only 5 bullets in my old six shooter because I had to say goodbye to Mona