Although the bullet diameters are the same, the larger .22 WMR chamber does not support the smaller .22 LR cartridge. Firing the smaller .22 LR round in a .22 WMR chamber results in swollen or split cartridge cases, high-pressure gas leakage from the rear of the chamber, and bullets striking the chamber throat out of alignment, which can result in injury to the shooter or bystander and which does result in poor ammunition performance.