you could use anchoring cement not two part epoxy . small tub of cement its quick drying . mix to milk shake consistency and pour it in just under ribs . it wont shrink and does job well I used it in fore end and but stock. also hydraulic cement . also a cement it will cure in water and used to plug leaky foundations as it leaks . all are at home depot and lowes in concrete isle and less than epoxy tubes. ps it tightened up my groups well . don't forget to glue or epoxy trigger guard / it really helps stiffen stock up as well