One thing I've noticed is that some custom balls alter the physical "size" of the ball
More than once I saw a ball bounce off the post when it shouldn't have
Even did some testing on and offline and once in a while, the ball actually seems to have changed 'size'
Rens2sea's code only alters the mesh of the ball. If you want to add some other behaviour as well you need to subclass DB_BombFlag and you can replace the current ball with your ball using a mutator.
function bool CheckReplacement(Actor Other, out byte bSuperRelevant)
{
if ( Other.IsA('xBombSpawn') )
{
xBombSpawn(Other).FlagType = class'Deathball.DB_BombFlag';
}
// there is other code here but it's not relevant to your question
}
See how DeathBall uses a normal xBombSpawn for their own ball?