You should be able to hit something the size of a deer's lungs at that distance with no problem with that load. Omega's are nice scopes, just keep it about 3 power and turn it up on a distance object. At 40 yards you shouldn't have any problem. In the past couple of years I have started using neck shots about every time. No problem with any tracking. Check the muzzleloading forum, lots of great guys on there.