Because your 22 brief magazine has no markings it is not from Winchester. I haven't found a 22 shorter journal that was not the exact same exterior dimension as 22lr mag. I'm able to’t visualize how a mag, like you explained, could possibility be safe when inserted. A photograph might https://highimpactrounds.com/product/winchester-defender-12-ga-2-75in-1-oz-rifled-slug-00-buck-1150-fps-10-rd-box/