Simo used a Mosin Nagant and dressed in all white waiting for a Russian to wander into his line of sight.
It is also said the he kept snow inside his mouth to keep from exhaling "fog" and exposing his location
He is reported to have killed 505 people in under 100 days, averaging over 5 kills a day. More than anyone else has ever achieved making him the deadliest sniper in history.