Except, supersheep, that we are not necessarily (or at all) talking high velocity .22 LR's. As far as I'm aware, most easy to obtain legal weapons in the UK (I'm using 'easy to obtain' in the loosest sense imaginable) use either the lesser powered .22 long (I'm fairly sure this is the cartridge the rifles I've done all my target shooting on used) or the .22 short. Hell, I'm not entirely certain we didn't use .22 BB's, which can be stopped by a decently starched shirt. I'm also relatively sure that most weapons in the UK are subsonic. (I don't know any of this, and the legislation isn't that detailed, but I'm assuming certain restrictions rule out other things at the same time) Also, I'd like to point out that, even with ideal ammunition, .22 rifles are mainly used for hunting things like rats. There's a biiiiig reason for this. The problem isn't the amount of soft tissue damage a .22 can do, which is appreciable (though inferior to almost every other sort of bullet), but rather its ability to penetrate bone. Put bluntly, beyond about thirty/forty metres, there's a big chance that .22s will just bounce off a zombies fucking skull, especially if it's fresh. From what I can find, .22s in general are useless for hunting anything bigger than a coyote, and even then you need to get a fairly good shot in from no farther than about 50 yards, using the best weapons and ammo. Remember, UK gun law is designed around only allowing very limited access to weapons that have the least possible utility in the killing of human beings. Probably the best thing that you could hope to get hold of (and this would need planning) would be the L98A1 Cadet Rifle, which, whilst not being civilian issue, is I believe probably the only non .22 or smoothbore fire-arm kept in any quantity outside of military bases and specially secured shooting sites like the Bisley range (Game wardens who control deer populations use larger calibre rifles, but that's like looking for a needle in a haystack). The L98A1 is bolt-action, and the action is deliberately very awkward ( you have to reach over the top of the gun with the left hand each shot, normally) but it's NATO 5.56, it takes STANAG magazines, and it has adjustable aperture sights. Raid a cadet unit for some of those suckers (praying they don't just have bolt action .22s like my old unit) and a few boxes of ammo and you're officially one of the best armed men in the UK. The other big option, of course, is criminally obtained fire-arms, but you've got a similiar problem to finding your game wardens rifle, not to mention you'd almnost certainly have to enter a big city to get your hands on one, and as far as I'm concerned 'do your best to get out of fucking cities' is a pretty hard and fast rule in the zombocalypse. The other major problem would be obtaining ammunition. Know how much 9mm ammo there is in the UK? Not very much, and you can bet your ass some Scouser gangsters probably unloaded most of it into a zombie swarm in Toxteth.
Also, I'd like to point out that we're all, maybe even me, though my plans are flexible, making a really crucially erroneous supposition here. Basically, we're all expecting Zombie Survival Guide/Russo zombies. This is a conditioned media response, people! What if 'Kill the Brain, Kill the Ghoul' is as empty as 'Duck and Cover'? What if we get classic Night of the Living Dead zombies, where the bite is not infectious, but generally fatal, and ALL recently dead re-animate within 5-10 minutes. What if we get later Romero zombies, who develop a degree of intelligence, or at the very least a thoughtless acting out of their previous existence (sometimes people forget that there's a REASON the zombies go to the mall). What if the zombie uprising, when it comes, is a purely supernatural horror, rather than a twisted scientific one? Perhaps the only sure ways to kill a zombie will be the same as the only sure ways to kill vampires (decapitation and burning). Speaking of burning, will we have zombies that dislike fire, instinctively moving away from it (a big bonus) or will we have zombies that merely shamble mindlessly through fire, setting themselves ablaze perhaps, but otherwise unharmed, maybe stumbling on for several minutes as flaming, crumbling edifices of mindless hunger, igniting us even as they gnaw on our bones.
Oh, and one more point. Someone earlier, I just remembered, opined that swords would not be effective against zombies. I think this implies a certain lack of understanding of how you use a sword, and how it works. Whilst some swords would probably be useless against zombies except in the hands of a very skilled wielder (epee's, foils and other stabbing weapons particularly) most western swords in particular would be fairly effective, as they are really mainly hybrid cutting/crushing weapons. Broadswords, as a category especially. They were designed, after all, to be effective against men wearing chain and plate armour, padded out with stiffened leather and sheepskin, and using shields. Zombies are not likely to be so well dressed for a scuffle, although a unit of zombified riot police might give you pause for thought. Other varieties of sword are likely to be pretty effective as well. Properly maintained ones designed for actual combat, that is. That's always a problem nowadays. Katanas, scimitars, cutlasses and other slashing weapons would take more skill to use than a broadsword, but not too much. My basic plan for taking down massed zombies with an axe would probably be a basic figure of eight, keeping the weapon moving all the time, and you'd want a similiar plan for such a sword. Never mind if you waste a few blows hacking off arms or whatnot, sustaining momentum is the most important thing: the one huge disadvantage of broadswords, and axes maybe, is the likelihood you're going to get one stuck in a zombies skull, leaving his mates free to dine on your delicious meats. If you kept it sharp enough, you'd be able to consistently slice clean through a zombies skull if you got it square on the side level with the eye-sockets.