going great guns

To do something enthusiastically and successfully. Primarily heard in UK, Australia. He was hesitant at first, but now that he's been on the job for a month, he's going great guns.

Fig. going fast or energetically. I'm over my cold and going great guns. Business is great. We are going great guns selling ice cream.

Proceeding vigorously. This term comes from British naval slang of the late eighteenth century, when blowing great guns signified a violent wind or storm. Another meaning for great guns, important persons, persisted throughout the nineteenth century, whereas in America the term was also an expletive for astonishment, comparable to “By George!” or “Great Scott!” It is the naval meaning that was transferred into the slangy cliché, however.