Drill a small dimple in the stock where the back screw goes. Buy a set screw to fit that thread count, lock tite.
There are 3 kinds of people in this world.
The wise, learn from the mistakes of others.
The smart, learn from their own mistakes.
The others, well......they just never learn.
"Is life so dear, or peace so sweet, as to be purchased at the price of chains and slavery? Forbid it, almighty God! I know not what course others may take; but as for me, Give Me Liberty, Or Give Me Death!"