Given that your 22 limited journal has no markings It's not necessarily from Winchester. I haven't seen a 22 brief magazine that was not exactly the same outside dimension as 22lr mag. I can’t envision how a mag, like you explained, could risk be protected 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/