I don't keep layers at the moment. I do, though, keep quite a few pens of gamefowl.
I can expect around 60 eggs per season from the hens and maybe forty from the pullets. However, I work a system which resuts in each bird laying slightly fewer eggs over the season.
I have always tried to give them as much freedom as possible through spring and summer...at least as much as surrounding crops and foxes allow. This means that some pens may only get out to free-range every third day, as I let a different pen out each day, or sometimes half-day, on a rotation. When they are restricted to their outdoor runs, they are on straw and fed wheat only. I always get plenty of eggs, and the hatch-rates are very good. The females are very broody, so they incubate their own eggs or those of other game hens. The chicks are always keen to get on.
I usually take the first 12-15 eggs from each bird for the kitchen, then let her lay a clutch for hatching, If she lays more than fifteen, I cream the surplus off daily until she goes broody. After hatching, her chicks will be with her for 5/6 weeks. After that the birds are then put back into the laying routine, and I'll get a second successful hatch from a selected few, whilst any eggs from the others are for eating. These second broods are with their mothers until the hen enters the moult.
I have found that the pullets are unlikely to lay much after the moult, being more likely to grow a bit, but I have, with the use of lights, been able to start the hens laying again and can get a further 2 dozen or so eggs from each. This is all possible from duration-limited free-range and wheat.
Free-range is important to hens in lay, and must be taken into consideration when planning feed, but more important is how they use it. Some breeds, and even some individuals within the breeds are much better foragers than others. There are hens which are quite happy to keep popping home for a quick bite, whilst there are others who will spend much time ranging and hunting for food. If there is a tendency on the part of the keeper to ad lib feed, or to feed heavily in the morning, many birds will be less likely to forage as widely as they may otherwise do if left to their own devices for the early part of the day.
Hens eat what they need to reproduce in those circumstances, and mine eat grass, worms, and insects, as well as the wheat I supply at the rate of one handful/head/twice daily.
When I have kept layers in the past, I found that if they were given enough free-range, and one third oats to two thirds wheat, they would lay well enough for our needs. With lights they would lay through the winter, and we always had some surplus.
I suppose it all depends one what yield is required. I don't have great expectations, so tend to feed by what I see in front of me and the results I get, rather than what it says on a bag.