As Chuck in Denver states, you need to repair both the recoil lug area as well as the tang. I salvaged a split stock (worse than yours) by using acraglass on the recoil lug plus the tang. In the tang area, I removed some wood and then drilled a .375" dia. hole into the wood at about a 45 degree angle about 1" deep. I filled it with acraglss mixed with wood shavings. I then glassbedded the action to the stock. It is still sound today many 1000s of rounds later.

Pinned 1903 stocks are well known for splitting.