IR video of India's Agni-3 test

[amardeep mishra]

Missile goes supersonic after 30 seconds of launch.
First stage Burnout at 87 Seconds
All stages Burnout at 3 Minute 08 seconds.
Since its a two stage Missile, the second stage burnout time must be 100 seconds.

Start watching the video at 3:27

Hi shaheen!
There is no doubt you managed to pull out a very old launch video with telemetry tracking of Agni-3. A lot of things have changed in past 6-7 years. If you're so interested in comparison, Let me point a few things for you-
1) Agni-3 was infact graduation step for DRDO, they managed to design a 2m dia rocket and integrate it into a system. Agni-3 featured a lot of "new" technologies for the first time-- like flex nozzle, thermal skirts etc to name a few. The missile was no doubt heavy as it used maraging steel throughout. I guess that is the reason why it accelerated slowly compared to lets say Agni-4. That being said, the weight of agni-3 has been reduced considerably and some accounts suggest new weight to be in vicinity of 22-25tones.
2) Let me take this opportunity to point out certain aspects of rocket motor design in both India and Pakistan. And I am sure @The Deterrent would agree-
Here is the rocket exhaust of Ababeel-

This one here is the rocket exhaust of Agn-3-

Now what you're about to see is the exhaust of French M51-

In all these cases you can clearly see, that Pakistani missiles are at least 2-3 generations behind the french one and at least a generation behind the Indian one. Now, instead of scowling at me for biased writing, hold on, relax and start thinking rationally. I am not into propulsion, however I know enough to explain a lot of things here. Also my area of expertise is nonlinear and intelligent control.
So, let me explain as to how or why I claimed it to be the case-
(a) The divergence losses of Pakistani missile is "horrible"--no other word to describe it. There is no doubt that most of the nozzles are designed to operate optimally in certain altitude band, however in other altitude bands the divergence losses should be as less as possible. In Indian missiles starting from Agni-3 and Agni-5 the divergence losses are particularly low, this is in stark contrast to the Pakistani missiles that exhibit higher degree of divergence losses implying inefficient nozzle. I tend to think that Pakistan has taken safe route of using conical nozzles instead of Rao or Bell nozzles. And yes Rao nozzle was pioneered by an Indian engineer working for NASA back in 60s.
(b) India has long moved to higher density propellants and in fact is working on ester based propellants for K-5(the picture you saw a couple of days back). This means K-5 propulsion would be in the same league as Trident or M-51. However how far DRDO is able to pull off miniaturization is remain to be seen. But going by what is happening on this side of the border, K-5 has superseded almost every strategic program in India.
(c) I am not even touching upon the truss structure separating two stages in Pakistani missiles or the flex nozzle.
(d) Designing a giant, heavy weight missile is no feat, what is truly an engineering challenge is to design a missile with least possible weight and dimensions. Lets take the case of Agni-4 that weighs roughly 25t and can pull off 4000km and shaheen-3 that also weighs 25t and can do 2750kms. I am sure, this would tell you the level of miniaturization achieved here.