CCI Mini-Mag .22 LR 40 Grain CPRN: Ammunition Shelf Life and Long-Term Stability When stored properly, CCI Mini-Mag .22 LR 40 Grain CPRN exhibits strong long-term shelf stability. Rimfire ammunition is generally more sensitive to environmental factors than centerfire cartridges, but Mini-Mag is produced with stable priming compounds designed to resist degradation under normal stora... https://bulkammotogo.com/product/22-lr-40-gr-cprn-cci-mini-mag-0030-5000-rounds/