BTW; Russian manuals say nothing about fixing bayonets when the MN M91 or the M91.30 "is brought to normal zero". Pictures in the manuals also do not show bayonets fixed in pictures showing the various shooting positions.
What the manuals do say with regards the M91/30 in particular is the rifle is zeroed at 100 meters with the rear sight set on 300m. For the M91/30 to be considered "zeroed" with the M1908 light ammunition ("L" Ball ammunition) Shooting 4 shot groups the center of the group should be (I'll roughly convert from CM to inches) 4.75" to 8.6" high above the point of aim and deviate not more than 2" left or right. Maximum group size for the 4 shot groups is 6 moa.
The manuals indicate this zeroing procedure is conducted at unit level with unit armorers assisting by replacing front sight posts and drifting the front sight for windage if needed. The manuals say nothing about the rifles being zeroed at the arsenals. Thus with all the arsenal reconditioned MNs imported many, if not most, may not have been zeroed by actually shooting at all.