I have way too much time so I did some quick checking. The question that I had was "which side arm is the best for zombie killing" So then I started thinking, what makes a good zombie killing weapon: they all put out similar "damage per second", they all have crappy range (20-30m max). Next up: if you get them indoors, they all are just as good - slowly line up headshots, relax.
So I think one of the key metrics for what makes a good sidearm vs zombies is how many of them you can kill per inventory slot. Inventory slots for pistol ammo are limited and most people carry 1-3 bandages there already, others like m203 rounds in there too - so ammo efficiency is a big thing in my opinion.
Consider a zombie has 4400 blood (dayzwiki). The following rounds required to kill a zombie: 45acp - 4 hits. 9mm - 5hits. So lets check by magazine size:
How many zeds per magazine/inventory slot arranged in terms of ammo economy:
PDW with 30 rounds kills 6 zeds
G17 with 17 rounds kills 3.4 zeds
m9/sd with 15 rounds kills 3 zeds
m1911 with 7 rounds 1.75 zeds
revolver with 6 rounds 1.5 zeds
makarov with 7 rounds kills 1.4 zeds
Note that the bottom 3 will only kill 1 zed before they have to re-loaded. Also, we're talking about body shots here. as far as i know, all headshots from all weapons put down zeds so doesn't really apply.
PDW is a clear winner in the player vs zombie department in my opinion. PDW ammo is hard to find of course but in a pinch you can just substitute other ammo types which in turn puts them on par with these guns in terms of ammo efficiency.
I think that while m1911/revolver have nice damage (don't forget, ammo re-combining is getting fixed soon) these two guns are slowly becoming less ideal.
I think this trend is also sort of inline/balanced vs ammo/weapon availability:
mak/revolver/m1911 are very very common - you can find them in almost any spawn pile. Meanwhile the better weapons are increasingly rare - with PDW being towards the upper end of rarity.
I think in terms of pvp - if you are using pistols for pvp, which in many cases is fine - the metric should be different: damage per second - because the pvp encounter using pistol is mostly about "how quickly can i put him down before he gets some rounds into me" - but I don't have rate of fire stats for pistols at hand. However, I think m1911 would be very high because it fires so damn quick (and higher damage) - with PDW being either first or equal first in terms of getting rounds into dudes - provided you can remember to set it to auto instead of semi