Sorry i had to post it there because when i try to put it as a tutorial the server crash.. no idea why but there is an error in the loop of an object.
This is a short tutorial on how to create pixel-perfect collisons with bullets. I will share my experience too about how its best to make it work.
The idea is basically to use a LOOP to move your bullet instead of using the bullet behavior. This is more precise.
I found something interesting... when you actuall create your bullet be sure it is positionned at an integer value position which mean you have to round it cause it will create problem once it reach the wall. The collision work with pixel integer value so if your bullet is created at lets say x: 233.444 it will move along the non-integer value of .444 and when it reach the wall it will obviously pass the wall off 1 pixel. I am saying this cause this mostly happen if you use the movement behavior as the firing object. Cause that object is never at an integer value so creating your bullet at x,y of that object isn't a good idea. The project option round pixel doesn't seem to fix this issue so be careful.
Thanks to MadFactory since he referenced a MMF base idea on how to do it.