I need to prevent projectiles from exiting an object (equipped shield) while allowing them to enter.
The point is to have a shield of flesh which regenerates.
Currently it allows bullets straight through, injuring the actor.
How can I stop them from exiting?

Make it out of dummy heads, those things are magical.

But seriously, take at look at their properties, wounds, and wounds' properties, might help.

Well I tried copying their wounds and material, to no effect.
I've got an idea from this though, thanks.

I replaced the shield with a much thinner sprite, then added an attachment to it, using the original sprite.
The thin layer is in front and can take damage, while the main sprite is in back and deflects projectiles.
Currently I'm trying to align them just right so the damageable part covers the visual one.

Edit: Nope, doesn't do it. Only works when in reverse; blocking from the front and hurting from the back.
I swapped through every combination of sprite/property, so I know the attachment/device placements don't matter.
Reason: Whenever a bullet makes an entry wound in any part of the shield,
the bullet somehow exits directly inside the actor/user, immediately harming them.
I keep seeing the bullets enter at the tip of the shield, then reappear some 10 pixels lower, at the actor's center.
It does this with different vanilla actors and my own.