My suggestion: you aren't aiming at a point on the outside of the deer. You are aiming at a point on the inside of the deer - with a view to destroying something immediately vital to the deer's life. Have a look at pictures of a deer's internal anatomy from various angles, or have a really good look at the anatomy of the next one you see dressed (if it hasn't all been turned to jelly by the bullet) and visualise that as you aim.
The heart lies low in the chest, but a hit there generally sees the deer bolt, even though they usually don't go far, and so you may have to go find it. Above that though there is important plumbing, heading up toward the spinal column, which dips fairly low between the shoulders. There is also a major nerve junction behind the scapula, coming off the spine. A bullet in this space will usually do a fine job, and if on the way it goes through, say, the socket end of the scapula the result is usually amplified by bone splinters. If you are high above the deer you may be putting it in between the upper edge of the scapula and the spine, or directly into the spine. From directly in front the shot into the spine in the neck through the front of the neck also suggests itself or, if the deer puts its head down, into the spine from above. The point is though to think about what you want the bullet to transect, inside the deer, not about things like where the "front shoulder" is.
