Thank you very much Anandalal, and I appreciate the references you have added here as well. It is interesting, as I noted earlier, that Pant, in his 1980 work "Indian Arms and Armour" , nowhere makes reference to the 'zaghnal' or 'jaghnol' or any variation of it, dagger axe etc.as far as I can find. He does make note of the Sindhi 'bhuj' , which is of course a hafted knife mounted inline with the shaft though.
While he discusses Rajputs and Rajput weapons, it seems odd that these are not included in a work widely discussing Indian arms.
Dr.Pant did write numerous works, as I understand he did work with the National Museum in New Delhi, but I was not aware of this title from 1995, "A Catalog of Arms and Armours in Bharat Kala Bhavan", written with Yashodha Agrawal. In this work, the 'jaghnol' is included. I am absolutely no linguist, but would I be correct in assuming the use of the letter 'z' in place of 'j' would be a Persian spelling characteristic?
In checking other sources, I have two books by E.Jaiwent Paul, and cite them here even though they are decidedly general in scope. They do however, emphasize the Rajput's in reference to the weaponry discussed, by the broader references to them in various text.
"By My Sword and Shield" (E.Jaiwent Paul, New Delhi, 1995), on p.84,
notes that according to Pant discussion on battle axes, "...another type was the zaghnol (crows beak) in which the head was pointed and provided with two cutting edges".
It would seem that Pant, by 1995, was including the zaghnol in his discussions, but as quoted by Paul, used the 'z' in the spelling. Perhaps the co-author used the 'j'...who knows?
I dont know on Nicolles reference, but every reference I have seen from Egerton, Stone, Paul, and the later Pant reference use zaghnol.
Probably not relevant, but curious.
In E.Jaiwent Paul's more colorfully illustrated "Arms and Armour: Traditional Weapons of India" (2004) the 'zaghnol' is illustrated p.99, using the same text from his previous book. The example shown is from Rajasthan.
Still not finding the 'hamstring' note, but it seems well established these type dagger axes were used by Rajputs, and it does seem that many of the references note cutting edges, despite emphasis on armor piercing blows. The reinforced tip seen on these resembles of course the malle perce tip on the katars and many of the edged weapons incl. 'zirah bhonk'.
It would seem that the spike atop the head would serve well in stabbing at mail in close quarters, and as many Indian weapons, provide multi functional elements in combination.
Thank you again for these additional references that I can add to notes,
All the best,
Jim