a movie similar to the dirty dozen?

I remembre as a Kid watching a movie very similar in its plot to the
dirty dozen, but I can't remember its name. also 12 convicted soldiers
were chosen to assassinate a prominent german officer, and when the
sniper in the group (a black actor) aims for the German officer, the
officer is standing next to Hitler himself. he hesitates whether to
kill the officer or Hitler, but in the end he follows commands and
kills the officer, afterwards, the group attack the german camp, and
most of them die. except 3 and the major John. the black sniper dies
from internal bleeding in the fleeing stolen german helicopter.

if anybody knows this movie, I would be very very grateful if you
could reply with its name, i've been looking for it for ages.... with
no avail.

thank you for your time