Determining proper seating depth is probably one of the most important steps in preparing accurate, custom ammunition for your own rifle, unless you are loading for functionality in a magazine.
Finding the best bullet seating depth for a specific bullet to be used in an individual rifle is critical to the accuracy level that you are trying to attain. A huge benefit of handloading over factory loads is that you can change the overall length of your loaded rounds. The impact on accuracy can be very significant, probably more so than anything else you can do other than choosing the right bullet and powder combination. Let’s define a few terms first.