that picture has been used a lot- its in the likbrary of congress collection -- Rio used a doctored version in their advertising a couple years ago. i think i first saw it in Walsh's "Outlaw Gunner"

if you search on "punt gun 1923" you will find several descriptions in English


http://www.vintag.es/2013/07/punt-gun-washington-dc-1923.html

search Bing for a German to English translator and cut and paste the verbiage into that to read it