The paper presents result of comparison of Cu content variability in three industrial ore streams, that is on section and transfer conveyors as well as the feed for the processing plant. Comparisons were focused only on ore grade variability for consecutive shifts during one month. The samples were taken manually throughout the whole shift from the transfer conveyor and automatically from the conveyor which provides the ore to the concentration plant. The comparisons indicated that the smallest variability of Cu content can be observed for the feed to the processing plant with coefficient of variation (cov) equal to 5.33% and the biggest for the ore stream on the transfer conveyor with cov equals to 11.85%. The grade distribution for the transfer conveyor cannot be described by normal distribution, as it is the case for the ore going to the processing plant and the ore supplied onto the sections conveyors. The smallest variability in the feed to the concentration plant is a consequence of almost perfect ore mixing and averaging of the ore due to coming from different locations and bunkers. The mixing is only partial on the transfer conveyor because of smaller number of ore sources as well as time separation between following loads from the mining faces. This gives in effect larger, instead of smaller, spread between the minimum and maximum Cu content. The spread was 1.36% in comparison to 0.45% for the processing plant feed and 0.99% for the section conveyor. The distribution was not symmetric. The standard skewness for the transfer conveyor was 4.79 in comparison to 0.2 for the processing plant feed and 0.96 for the section conveyor.