UKH

looking to buy my first set of ice screws. What would people recommend for a general Scottish winter rack for mixed grade III?

I was thinking maybe 4 screws, one short, two medium and one long?  

Everyones experience is different but personally, I would carry 2 short and 1 or 2 medium. I wouldn't bother with a long screw (>17cm), but carry a warthog and / or bulldog instead. I've used warthogs and bulldogs more often on mixed ground that ice screws.

For sure, it is always nice to think you are going to find lovely thick water ice to get a 22cm screw in really deep, but this is Scotland we are talking about

TJB.

What ever length you go for just make sure you go for ones with a speed handle for placing, Black diamond express for example, don't be tempted by the cheaper ones without a swivel handle, remember there expensive things to drop! As for length then what you say is fine, however if I know I'm on a mixed route, I wouldn't carry more than 2 screws anyway. If I'm on more of a snow/water ice route then I always carry a 22cm one to use in the belay with another medium or an abakolov. Most importantly is how you rack them on your harness, one of these will pay dividends when your reaching for them or trying to keep them put! https://www.decathlon.co.uk/simond-rack-id_8273617.html#v1665354 

Tricky one...

For most lower grade UK/Scottish routes I probably wouldn't carry screws but would more often have a warthog & bulldog with me. For a few routes I might carry two short/mediums and I wouldn't be at all bothered about the exact make model as I'm not going to be placing them whilst hanging from my axes on steep ice. Also the chances are that if I do place screws they are not going to be in massively thick ice so will often "bottom out" resulting in them getting minor damage or in some cases major damage to teeth. As such, there is a very good argument that there is no point buying really expensive screws to carry on this type of route.

That said, for a tiny minority of lower grade ice routes (e.g. Tower Scoop on Ben Nevis) then I would want a proper rack of half a dozen screws just in case. At that stage I'd start to be more concerned about ice screw design. Although for grade III/IV ice routes it's still very easy to cope with a mix of makes/models. The worst case is that you might have to place one or two on lead in steeper ground (where you use your best/sharpest screws) but the other screws are still likely to be placed from good stances or at belays.

However, if you want to future proof your rack for harder ice routes then you'd be better off picking a specific make/model of quality ice screw (and associated racking system) and then sticking with that.

As I said, slightly tricky decision. Short term it makes sense to go for any cheap but still decent screws, potentially even second hand. However, longer term it may make more sense to go with a single top-notch option.

HTH

Black Diamond express or similar with the swivel handle as already posted. We use 13cm generally with a 10 in reserve. Just as an extra, we've got 2 Black Diamond Peckers and have found them quite useful.