Fulton

NEVER NEVER use a hammer.
The correct way to do this is to apply lots of penetrating oil over several weeks. Then grasping the barrels at the extreme ends with the toe of the stock facing to the right, swing the gun in a violent horizontal left hand arc at a speed not less than 30 m/s. The comb to impact a firmly rooted tree.
I find Mahogany to be the best.

Regards