Hornady LNL Ammo Concentricity Gauge
This tool identifies and eliminates bullet runout (or wobble). Just place ammunition in the tool, roll it, identify runout and use the dial indicator thumbscrew to adjust.
Provides improved accuracy for handloaders, and can be used to true up factory ammo too.
Fine tuning for groups?By: Anthony on 8 October 2020Maybe. If shooters were machines that simply repeated their actions identically, then perhaps we would have no need for this tool. We spend a lot of time on annealing, washing, resizing trimming etc but how often are we really thinking about case neck run-out? If you just shoot 22LR or shotguns, the answer is "never". If you are making your own bullets and you are wanting to tighten groups this might help you you a little. But this is based upon a process of elimination ... uniform loads, identical projectiles, trigger application, breathing ... if you have mastered most things and you still getting variations in groups that you can't explain? Then maybe this might help you rule out the concentricity issue. I think that it was a worthwhile investment, but I am a fussy reloader. I would recommend watching a couple of Youtube videos to help explain this device in simple terms ... https://youtu.be/v14xRR-zpcc & https://youtu.be/YTsOjt0ReRY