Certain collision groups have strange collision properties.

[Bagellll]

This is a weird one. Props that have been given the collision group "COLLISION_GROUP_WEAPON" (or just regular weapon entities) fall or move through players slowly. What I have observed with this is that though players don't collide with this group. If the object is going to move through the player (drop on their head) it will do so very slowly. Although this is the case, players moving through the object are not affected by this and it only affects the object's movement.

[Bagellll]

This may also be related to #28