The zeroing on optics(SOS, LRPS) are not set right for all guns. Using a range with 100m target intervals I found the zeroing to the optic seems to be carried over
from the base gun not accounting for the differences there for throwing the zeroing off by hundreds of meters.
MX 6.5 with a SOS/LRPS zeroed to 500m hits where aimed.
MXC 6.5 with a SOS/LRPS zeroed to 500m falls short of the target requiring an adjustment of approximately 2 mill-dots under the center to hit where aimed.
MXM 6.5 with SOS/LRPS zeroed to 500m shoots high requiring an approximate mill-dot correction of 1 and a half above the center to hit where aimed.
Same issue is apparent with the Katiba:
Katiba Carbine 6.5 with an SOS/LRPS zeroed to 500m is on target.
Katiba 6.5 with the longer barrel and a SOS/LRPS zeroed at 500m requires a correction of approximately half a mill-dot above the center.