Like Buck460 and FrankenMauser says, depends on the round. When using the powder in a rifle cartridge, not to much worry about accident.
The smaller case cartridges, .1 ~ .5 grains could be the differences between "that was fun" and "That was really stupid and PAINFUL"
If your powder measure will not hold the correct setting, I would look for another. You could get in the habit of throwing under the desired weight and then use a trickle to bring it to the correct weight.
I use a homemade copper spoon when I need to trickle the load to exact weight.
Inside Every Bright Idea Is The 50% Probability Of A Disaster Waiting To Happen.