Where did you get that code from lol. Its not in the mod I just made lol.
to make bundles 30k - <set xpath="/items/item[contains(@name, 'Bundle')]/property[contains(@name, 'Create_item_count')]/@value">30000</set> (IS WRONG)
Should be
<set xpath="/items/item[starts-with(@name, 'ammoBundle')]/property[@name='Stacknumber']/@value">30000</set>