Due to the fact your 22 short journal has no markings it is not from Winchester. I have never witnessed a 22 shorter magazine that was not precisely the same outside the house dimension as 22lr mag. I can’t picture how a mag, like you explained, could probability be safe https://highimpactrounds.com/product/winchester-super-x-308-win-180-gr-pp-2620-fps-20-rd-box/