Awesome, that worked. I'll also make sure to look at the FAQ next time.

But, one last problem. In windowed mode, the gun can't shoot through walls if clipping through them, but in fullscreen it can shoot through walls if the player entity is facing a very specific angle. This doesn't appear to be a problem with timing, as I have just tried to make the player entity create the bullets instead of the gun entity, but it results in the same thing. It has something to do with the position of the gun, because if I use the player's position for the ent_create, it doesn't clip through.

Anyone know what the problem might be?