Let's review a battle of the Napoleonic Wars and do a bit of counting. I tried to search for one optimal but on such short notice I had to compromise a bit. Still sounds all right for the purpose.
Battle of Eylau in 1807
This is a battle between the French and Russians (with a smaller Prussian contingent).
Why is it ideal for us? It's a middle sized battle, both sides are largely the same and the losses are quite high. It took the most part of two days, let's say 20 hours in all with longer periods when line infantry engaged each other.
Why isn't ideal? The weather can be blamed to counter my argument, as a snowstorm made fighting and targeting harder then usual. But the high number of casualties still speak of efficiency, also there wouldn't be any battle if their marshalls didn't think the weather adequate for fighting.
The two sides fielded 75-75 000 men. Now let's take a closer look on the French side.
They employed 32 line infantry regiments, about 1000 men each (or more), that's about 32 000 riflemen fighting like the Prussian experiment supposed. There were other types of infantry of course but their role could differ (like picketing, skirmishing, leading assaults against fortified posotions etc.) so they don't count now.
The French caused 20 000 casualities (dead and wounded) in all if we are generous 15 000 if we aren't. Let's say we are. Very few people surrendered during this particular battle however we don't know about the fate of some but let's make things simpler and assume all dead and wounded. So 20 000 it is.
The losses were caused by the three arms: infantry, cavalry, artillery. The field artillery was the most effective in that era basically they were the precursor of machine gun teams both in usage (for example grapeshot from point blank range can be seen as a parallel of impact of a machine gun) and in efficiency. While I would estimate the cavalry the least efficient in inflicting losses (in battle but during chase or harrassing it's a different story) but this particular battle had seen some of the greatest cavalry charge of the era resulting in some nice figting against infantry and between cavalry units. Probably with high losses.
So how much could these 32 000 brave young soldiers kill or wound? I'm gonna be very generous (and lazy) and say 10 000 (I hope this will keep the counting easy). How much were line infatry from these 10 000 who could die the way the Prussian experiments supposed? How much were other types of infanty, cavalry and artillery gunner? Oh no I won't go there. I won't calculating the uncalculatable, let's just estimate 8000 dead line infantrymen for the kicks.
How long these engagements took between infantry units? Sadly, no idea. There's no timetable of the battle available. Surely they don't stand there loading and firing through the whole 20 hours. Let's say lowly 5 hours. All the other were cavalry fights, arillery bombardment, marching up and down, charging and retreating, picking noses.
Summary: 32 000 soldiers inflicted 8000 casualties in 5 hours.