Chork's Puzzle 04

Difficulty Rating: 5

Nick was doing target practice one day. Unfortunately, he wasn't a good shooter and his shots landed all over the board! After 25 shots, he decided to go for a break. Here's a layout of his shots on the board:



His sister, Sally came over, took a look at the board and observed: "You are not a bad shooter actually - all but one of your shots follow a pattern!"



NOTE: In the diagram above, the shots are not labelled in order of how they were fired. The numbering is only for referencing to the first diagram so that you can point out a particular shot more easily.

Which shot (1-25) is the odd one out?
If you know the answer, post it in the comments section of this post.