Rifle/SMG Effective Range

[Gerry1]

I know that the Kar 98k Rifle has a range of 500m and a HE Kill of 1. Is there any way to determine what is a maximum "best" range for it to engage, i.e. before accuracy drops off too much? Same for say a Russian SMG unit. I know in general the rifle squad would have an advantage at a distance.

There is an AP Penetration Calculator that shows values in 50m aliquots. Not sure is there anything like that for rifles, etc. firing on infantry.

Thanks.