Written by Sierra Bullets Ballistic Technician Duane Siercks
Another very common question or problem that we get calls on here in the 800 Tech Room involves a step in the sizing process. Quite often we get the call where after sizing, the cartridge will not chamber in the firearm. This most usually is a bottle-neck case, and most of the time the individual has not sufficiently lubricated the inside of the case neck. When the case is pushed into the sizing die, the die reduces the diameter of the neck considerably. Then as the case is being taken back out of the die, the case neck is drawn over an expander that is located on the decapping stem. Without enough lube present on the inside of the neck, the amount of resistance created by the neck passing over the expander will often times cause the shoulder of the case to be pulled forward. If that happens, the shoulder will then contact the shoulder portion of the firearms chamber before the action comes to a close. Be certain to lube the inside surface of the neck before sizing. Then clean the cases after sizing to remove the lube from inside and outside. That will normally solve the common issue of cases not fitting in the chamber after sizing.