When reloading, you must anneal the cartridges periodically to avoid which malfunction?

When reloading, annealing the cartridges is essential primarily to avoid neck splits. Annealing is the process of heating the neck and shoulder of brass cases to relieve stress and soften the metal, which allows the brass to expand and contract properly during the reloading process. Over time, as cartridges are reloaded, the metal can become work-hardened from resizing, which increases the risk of cracks or splits during subsequent firings.

Neck splits occur when the brass becomes too brittle, and the neck can't handle the stress of being resized or fired again. By periodically annealing the cartridges, you maintain the integrity of the brass, ensuring it remains pliable and less likely to fail under pressure.

While neck splits concentrate on the structural integrity of the cartridge case, other malfunctions like stuck cases, failure to eject, and firing pin drag arise from different issues such as excessive resizing, improper chamber dimensions, or problems with the firearm's firing mechanism. These issues do not relate directly to the annealing process. Therefore, the significance of annealing is closely tied to preventing neck splits in reloaded ammunition.