Thread: Optilock Screws

I presume its a wood stock ?
Use the super strength epoxy that stays liquid and runny for a long time.
Smear it on then gently spring the wood somehow to let the glue suck into the crack.
Flex it in and out a lot of times but gently.
Wipe off what you can afterwards and tape it tightly together so the crack is closed while the glue sets.
Leave it to stand overnight in some way so the glue will seep in rather than out.
After 48 hr try and peel/flake off any from the outside, sand with 600 then 1200 on the end of a pencil eraser.
Put on linseed or other stock oil to fix surface and fill in the last of the crack.
I had this at the tip of my .303 foreend and 20 years later its still good.

If its a plastic stock there are special plastic glues where you write on with a pen then spot glue but I'm not sure how to get it into a crack.

Yep, pretty well the right approach. If the crack cant be opened up I drill several tiny holes down into the crack and force the epoxy in that way. Just dont drill right through your stock though.