A heavy recoilless rifle squad (the leader on the right, most of the members not seen in the photo) marching in forest at Sodankylä in Finland. The weapon is the Finnish 95 mm recoilless rifle (95 S 58-61). It is 95 mm and was designed in 1958–1961, the design probably being heavily influenced by a similar concept from the United States. The day the photo was taken was pretty warm, so the conscripts were allowed to dress relative freely.
<a href="//commons.wikimedia.org/wiki/User:Methem" title="User:Methem">Methem</a> (Mikko J. Putkonen)
CC BY 3.0
<span class="int-own-work" lang="en">Own work</span>