I've only been detecting for a couple years and I've only found 5 war nickels total (just one with my recently acquired EQ800), but I've found their VDIs to be quite interesting. The first four that I found were with Garrett machines: the first one was in a coin spill so the numbers were naturally skewed, but the second and third each came up alone (and I mainly dug them because I got enough of a high tone from an iffy, deep signal to encourage me to dig on the assumption that I had a copper penny or a dime), and the fourth was the only war nickel I ever dug that was a solid "true" nickel tone all the way around the target (but it was shallow at only 2" down). Because of my experience with the other 3 war nickels reading high, I was at the point that I believed all war nickels read higher because of the silver content. But after the fourth one read "normal", I air tested each of my war nickels and was surprised to learn that despite the high tone component of my second and third war nickels in the ground, all of these four war nickels read in the "normal" nickel range out of the ground. I definitely rescanned all of my previous holes, so there's no doubt in my mind that there wasn't a missed target on the lone nickels.
My fifth war nickel was found with the EQ800, and it's my only war nickel that was a solid 21 both in and out of the ground - it's a 1945 P, so it isn't just the San Fran mint that has the occasional high nickel - Philadelphia apparently had some as well. Rescanning my other four war nickels with the EQ, I get a solid 13 for all of them (two 1943P, a 1944P, and a different 1945P).