I’ve repaired cracked stocks on Perazzis, Berettas, Brownings, Benelli autos and others. Most of the time the cracks have started in the area of the upper tang. Repeated recoil and retightening has compressed the wood in the recoil surface of the stock allowing the upper tang to work as a wedge against the stock. The cracks seem to propagate either straight back from the tang or downwards across the checkering. Like dcblvsh2 I glass bed the recoil area after repairing the crack and leave a slight relief behind the tang.
Some of these guns had loose stocks when brought to me and some had been dropped or fallen on while hunting. I don’t think it is necessarily brand related. Sometimes it’s just the figure in the wood making a weak spot. I do think it’s important to get it fixed at the first notice of a slight crack as it will only get worse.
Soon after buying my used 1969 MX8 I glass bedded the recoil surface as the tang was bearing against the wood. I’ve had no issues in the years since. I do check my stock bolt on a regular basis…not too tight but never loose.
