Baikal IZ43 and IZ58s are engineered for mass production, so they have parallel tangs, ie they do not wedge the stock apart, and circular wedge shaped stock cheeks that mate into equally wedge shaped action recesses. Recoild reinforces the fit, squeezing the wood inwards, not outwards.

Good idea on an inexpensive double, but ugly and for most people unacceptable on an upmarket SXS. So the wedge tang rules alond with inevitable cracking losses.