I don't like the sort of target you are using as it does not complement shooter/target analysis. In addition, its color and design are distractions to the eye's natural ability to both balance and center objects. My suggestion, buy some 300 yard Military Decimal Target Centers. These scoreable targets will allow for recognition of progress. Also, three hundred yard shooting exposes angular errors which may be masked at less distance. Knowing this, you should recognize when successive bullets do not all go through the hole vacated by your first bullet strike that it has something to do with your relationship between gun and ground not being consistent, less than perfect ammunition, or wind not properly countered. Calling your shots and correlating to strikes will reveal the cause of most of errors. For example, shots on call but not perfect pin wheel X's means the position was not consistent or poor trigger control. Shots off call may mean wind was not correctly countered, sight not adjusted properly, or ammunition inconsistency.