Use the on collision with trigger rather than testing for overlaps.
EDIT: if for some reason you did want to manually set the Bullet ricochet using events:
Bullet 'On Collision With' Wall
- Bullet Set bullet Angle Of Motion to (angle of surface hit-(Bullet.bullet.angleofmotion/2))*2
Sub Event:
If Bullet.bouncecountervariable<>3 - Add 1 to bullet.bouncecountervariable
If Bullet.bouncecountervariable=3 - destroy Bullet