Just guessing it is 3" mortar shell of British/Australian/Canadian origin.Originally Posted by desbromilow
There are three distinctive features:
-blunt shaped fuse with a straight knurling(No. 152?)
-wide, single driving band
-three double fins with two holes in each half(some versions - not all - had stamped those reinforcing ribs), rounded on both ends.
One without stamped ribs:
ps. sorry for poor english
pps. it should be fins or vanes?