Hi Brian,
I have to admit I've been pretty much 'out of the loop'

on this oustanding discussion on mail and katars the past week, although I have read this thread as well as the one on the other forum. I think your discussion on Indian armour was very nicely stated and well placed, bringing up material on this armour that illustrates that there was a distinct spectrum of quality in the forms found. This suggests of course that some Indian armour certainly did parallel European quality. I think Ham made a particularly important comment concerning the validity of comparisons when significant difference in period are involved. Weapons and armour of later period that maintain certain traditional style or form vestigially, as their expectation of meeting the combat situations intended for original design is negligible, seem hardly worthy of such comparison.
The study of armour has admittedly been far outside my field of study, but in reviewing these discussions I cannot help but become profoundly intrigued and realize how important and relevant its study is to our more focused study on ethnographic weapons. The paper "Demystifying Chain Mail and Ring Mail" by Dan Howard that is linked in the thread is nicely written and beautifully referenced, informative and most helpful in getting the proper perspective in understanding this topic from the European forms. I agree with your note that most study of weaponry and armour does defer to Ottoman and Mamluk material when 'Eastern' examples are discussed, while Indian forms are relegated to broad assumptions and nearly cliche' interpretations. I think one of the most important qualities of Robert Elgood's magnificent new book "Hindu Arms and Ritual" (London, 2004, ISBN 81-88204-44-7), is that he brilliantly examines how to understand the symbolism imbued in the weapons and armour, an extremely important perspective that has typically eluded the scope of arms and armour study in the west. His work will stand as the renaissance of the study of Indian weaponry.
Returning to the topic of mail and katars, on the mail I would defer to the advanced knowledge of you and the others on these threads, and hope the discussions will continue as the material is fascinating and its great to learn more on this!
On the katar and it's use as a mail piercing weapon. You, Jens and I have of course discussed these often, and there have been countless posts over the years on these forums. With the limited material available on these, most of the discussion is naturally speculative. The suggestion that the katar was not intended for use against mail needs qualification. This is a weapon that evolved over a long period and seems to have remained indiginous to the Indian sphere, however with the development came of course variations. It seems to me that in its development in Southern India it was likely not meant to pierce armour originally. Much like the pata, its gauntleted sword big brother, it was used in slashing manner as much as in thrusting. It is important to note that the Mahratta versions after the arrival of Europeans often used the straight broadsword blades from Europe. These blades would have not been suited for mail piercing in India any more than they would have been in Europe.
In later development of course, encroaching influences brought the well known reinforced points seen on many of these katars that would suggest the potential for armour piercing. Obviously such a feature would not guarantee that it would be used for such purpose any more than it would preclude its use in any manner dictated by circumstances. With that consideration, it seems worthy of note that the absence of combat damage on existing katar examples that would indicate contact with armour does not necessarily provide evidence that such use was not intended. It must be remembered that most Indian weapons that survive are typically those found in collections acquired during the British Raj, and these were often armoury items or from gatherings from diplomatic interaction. The weaponry of the rank and file and with combat history typically ended up in scrap heaps and were disposed of. This severely impedes the possibility of combat damage on examples found for examination, much as in considerable weaponry usually found by collectors. It is truly a 'conquest' to find a 'dark warrior' that carries genuine combat damage.
I think that the katar was a weapon form that like most others, experienced variation, and while there were certainly examples that carried blades that were reinforced for mail piercing, this was not an exclusive consideration.
As far as the most effective attack against mail, it seems that in the heat of combat, the most instinctive action in the melee would be a powerful blow with a zaghnal, battle axe or mace. It would seem that in using blades against mail the primary concern would be in the blade breaking. Here I would ask those more advanced in armour...would there have been a construction location in the coats or shirts that were more vulnerable? It is of course said that a chain is only as strong as its weakest link. Also, would heavy blows from mace or axe sufficiently weaken areas of the mail to allow better penetration of a bladed weapon?
This has been an outstanding discussion, and I very much admire the prudent demeanor employed by you and everyone on this thread in discussing a concurrent thread from the other forum and avoiding direct criticism of its participants. Very nicely done!
With all best regards,
Jim