In the single player campaign, the M91 is not
available until operation 06, Raid on Nordsig,
Exfiltrate Nordsig.

However, it is possibile to obtain an M91 as
early as operation 02, Assassinate Borman, the
Supply Raid.

There appears to be two types of enemy snipers.
Those on the rooftops that are able to come down
to the ground are armed with the G43. Those on the
rooftops that are unable to get off the rooftops
are armed with the M91.

In the Supply Raid there is an enemy sniper with
an M91 located to the left of the first two
bunkers on the roof.

Position yourself on the right side of the road,
close to the sniper. You want the sniper to lean
out and get you in his sights, then you shoot him.
The M91 should fall to the ground.

The key is to force the sniper to lean out and
aim at you (yes, you are the bait) so that the M91
will fall to the ground.

Having the M91 so early in the game changes the
dynamics. You seek out different sniping locations
that are of greater distance from the target. The
bullet cams are longer and more interesting. Also
the AI reacts differently, because you are no
longer following the anticipated script and so
a different emergent behaviour occurs.

In every scenario there seems to be at least one
enemy sniper with an M91.