February 21st 2023
This inexpensive method can help you load straighter ammunition with slightly higher measured concentricity (i.e. There is less run-out on the bullets and case necks. Use a Rubber O-Ring to secure the die locking ring. This allows the die (slightly) self-align to the case being sized. Your die may be slightly off-angle if the flat top of your press isn’t perfectly square with your thread axis. This happens when the bottom end of the locking ring presses against the top of your press. The O-Ring allows for the die to float slightly which may reduce run-out during case sizing. Place the O-Ring onto the die, and adjust the lock ring to make sure that the O Ring is slightly compressed at the correct height. Measure a few more cases. As the die can now float slightly as the case enters or leaves it, you will likely notice a slight improvement in neck concentration. Although it is not going to be a significant improvement, it is a positive one. “We want to emphasize that O-Rings can be used to size dies, but this is not a panacea. It’s worth a try. If the O-Ring reduces measured ranout, that’s great. Lee Precision makes die lock rings that have O-Rings. Lee’s unique lock ring design allows for the same type of self-alignment. Lee lock rings won’t secure to the die threads so they can move as you insert or remove dies. This can cause slight adjustments in your die setting. You can still enjoy the benefits of the Lee design by using an O-Ring underneath a conventional die lock rings (that can be locked in position), but without the risk of it moving.
Similar Posts:Tags: Concentricity, FL Sizing, Lee Precision, O-Ring, Reloading, Run-Out, Sizing Die
