Yes. Follow up shot accuracy is important. The human body sweats. Most humans live near water. Meaning humidity. If you conceal, your ammo and weapon is constantly exposed to humidity higher than is generally within the environment outside your clothing. By cycling your ammo you avoid numerous issues. First and foremost, ammo exposed to high humidity isn't around longer than a year. Powder inside casings maintained within humid environments can have unexpected and unreliable performance. Feed lips on the mag can wear grooves into the brass if constantly recycled back into the weapon. Brass casings are soft. This can create feed problems if over a long enough time period. Finger oils, gun oil, and oxidation can create a gummy build up on casing. This can create feed problems. Aside from cost, there is only a good side to using your ammo annually.