Really? The earlier IS-2's D-25 is just an A-19 modified for use in a tank.7thGuardsTankDiv said:IS 2 gun is a long high velocity gun and therefore not a howitzer.
The term "howitzer" hasn't got anything to do with the length of the gun or velocity of the shell. It has to do with the ability to fire at high angles (I don't think you're gonna fire 122mm 2 or 3 clicks without a fairly high angle.
MOST howitzers TEND to have a caliber (barrel length to bore) of under 30, but the A-19 and D-25 are something like 48.