The 310+347+(330/1000) numbers were cross-checked at four levels at four different times -
1. When Defence Acquisition Council chaired by Defence Minister cleared it.
2. When Cabinet Committee on Security chaired by Prime Minister cleared it.
3. When actual orders were placed.
4. When the tanks were inducted.
This is the first reference i see to the 400 figure, and i didnt find any DAC or CCS clearance for its purchase.
Feb 2001 - 310 order signing between ministers reported http://www.indianexpress.com/ie/daily/2 ... 16053.html
Sep 2008 - 347 order signing between ministers reported http://indianembassy.ru/indiachronicle/sep08/
It was during the September 2008 meeting that russian non compliance in not transferring technology was resolved and the 1000 manufacture started. The 330 was ordered 2006-7 but manufacture could start only post September 2008
I believe the 400 number is a mis-representation of the 347 order 11 months ago.