Entity Subtype for custom bullets

I'm trying to make a bullet that explodes while flying without blowing up the bullet in mid air. I used this code here 

if ((((entityiterator instanceof PlayerEntity) == (false)) && ((entityiterator instanceof ArrowEntity) == (false)))) {
                    if (world instanceof World && !((World) world).isRemote) {
                        ((World) world).createExplosion(null, (int) (entityiterator.getPosX()), (int) (entityiterator.getPosY()),
                                (int) (entityiterator.getPosZ()), (float) 1, Explosion.Mode.NONE);

But it will still explode even if I select sub type as arrow. Which really doesn't make sense because isn't the bullet just a arrow entity? Basically what I'm trying to say is there a sub type for custom arrows entities.