Thread: longer range hunting

Hi guys i have a friend who has access to a very large property down the line with really good deer numbers so we are looking to head down before the stags drop so i can knock over my first red and hopefully my first stag(one animal would be ideal haha). I am running a tikka 308 with a 20" barrel and a hardy can mounted with a bushy 4200 elite 3-9 standard crosshair, now i am confident that the scope is up to the job power wise but i need to learn to shoot with bullet drop for the calibre unless i splash out on an early birthday present and grab a Nikon monarch or a vortex diamondback with the BDC reticles(use as a guide more than as a bible) so my question is how far out would you be confident shooting a big red with a .308? There is a lot of open country so most of the guys shoot with 300s and my mate uses a 6.5x55.
I have zeroed the rifle at 100m rather than 200m so in the bush i do not need to aim low.
regards