I think that all hunters would of liked a better shot but it sounds like you took the best shot available to you. It sounds like you had a small window of oppurtunity in a small shooting lane.

I amy not have taken the shot depending on the buck and available time to continue hunting. You should never have to question your shot, only you know what you are comfortable with. Confidence In your ability to make that shot has to be the primarly issue. If you were confident in your abilty and your equipment I believe you try to harvect that deer.

If not you should wait for a better opportunity.