Since your 22 brief magazine has no markings It isn't from Winchester. I have never noticed a 22 brief magazine which was not a similar outside the house dimension as 22lr mag. I am able to’t consider how a mag, such as you described, could likelihood be safe when inserted. https://highimpactrounds.com/product/winchester-target-7-62x39-123-gr-fmj-2355-fps-20-rd-box/