If you are a precision shooter, you care about consistency for the cartridges that you shoot. One of the most important factors to measure and control when reloading match ammunition is bullet concentricity. Simply stated, this is the alignment of the case and bullet. If you have “good concentricity”, you will have the axis of the bullet and the axis of the case close to collinear (on the same line).
In this video, we’ll measure the concentricity of the ammunition that we’ve been loading in AR-MPR Phase II – specifically when we seated the bullets in the previous video: AR-MPR Phase II – Seating Bullets. We’ll also use the included adjustment screw to dial in our runout (lessen it when needed) so that we have +/- .0005″ measured runout. Note that each measurement tool measures runout differently, so you’ll need to factor that into your goals for your own match ammunition.
In addition to checking and correcting your own handloaded ammunition, this tool is also great for checking and dialing-in off the shelf commercial ammunition. I might just have to go through some of my prior loads in different calibers to see how well I did!