Thanks Dave, but while that works, it takes a lot of space. I as hoping to hear that there was a built-in way that accounts for it. It doesn't look like there is though.

Richard

I'm not sure where to post this, because it's not a bug, but a technical detail.

It seems like .13's awesome ability to pickup/drop off more than one item with inserter tech upgrades makes it impossible to fill a container with an exact number of items. I apologize if I'm wrong, and just missed a ...

I've attached the save file with the issue.

It contains filter inserters, attached to a Arithmetic Combinator, which is attached to a Steel Box. The combinator simply multiplies by -1.
There is a constant combinator attached to it, providing positive values.
The filter inserter is set to use the ...