I found the text online Nandi-Purana from Vysaonline site
I thought of adding this to the question instead of answering this way, but then the question won't make sense any longer.
I thought of deleting this, but then felt this might be a useful entry for someone else who may be interested in the future.
Hence decided to post this as an answer. If others ...
For this we have to do comparison of scripture as per the scriptures
Devi Bhagwatam 11:1
Where you will find differences between S’ruti, Smriti and Purânas, accept the words of the S’rutis as final proofs. Wherever Smriti disagrees with the Purânas, know the Smritis more authoritative. And where differences will crop up in the S’rutis themselves, know ...
Don't know about weapon like brahmastra but some other majical weapons are present in vedas.
Your Soma-drinker keeps afar your furious rush, Indra and Visnu, when ye come with all your might. That which hath been directed well at mortal man, bow-armed Krsanu's arrow, ye turn far aside.
Here, Vedas tell about Krsanu's arrow. I think ...