There is no "bulletpass" command. I do recall making one and it's likely that it was called "bulletpass", but it's most likely that I removed it and kept the AirMod version which, as hockeykid has pointed out, is called "nobulletcol".
Place "nobulletcol=1" into your entity's script to remove bullet collision from it (Allowing bullets to pass through your entity). Use "=0" to give bullet collision back to the entity.
@Jimmy:
No release date is official for v1.8 of PB. It's possible that very soon, neither s4 nor myself will be able to work on PB for a long time. If that becomes the case, we will likely find one or more people to take over the project for us. It's not our intention to let the project die off.
@Arenas:
There are two ways I can think of to do an animated HUD, one of which is doable in vanilla FPSC. One would be to load up multiple HUDs and swap between them in a script to give the illusion of animation. The other would be to make a decal, and have that decal reposition itself in front of the player, so that the player is always shown the animation.
The one and only,