Dedicated AK74 Optics
It shouldn't really be a
surprise if you're into AK's but the Russians have
produced a number of newer designs for the AK74 than
just the older PSO/POSP series optics that we are
familiar with. During the past twenty odd years they have built a few dedicated
5.45 optics which have modern features and interesting
concepts. While NPZ has been making some high tech and
interesting optics, BelOMO has seemed to stay a little
more traditional with their designs, at least with
what we have available in the US. Some of their
prototype optics are extremely interesting. Many of
the BelOMO concepts seem to be aimed at securing
military contracts and because of that there are a few
prototype models that have made their way to the USA
that are not in serial production.
Note that other than the similar Zeiss ZFK there are no known versions of the PSO or POSP that are calibrated in 5.45x39. There are ways to use these optics with AK74 type rifles but none that are designed specifically for them.
Being a 5.45 buff I've picked up a few of the dedicated military style 5.45 optics and figured I'd put out some observations and theories along with some hands on experiences.
Originally there were four main optic types
calibrated specifically for the 5.45x39 round, but
recently BelOMO has introduced the PO4x24P2:
1P78 Kashtan - Russian modern issue for AK74M and RPK74
(Includes 7.62x39 versions as well)
Zeiss ZFK 4x45 - Former DDR cold war scope similar to the PSO-1
I have not personally heard of a PSO or POSP type optic calibrated for 5.45x39, but it shouldn't be difficult to use any of them with a 400m zero as long you realize the turrets and additional chevrons won't compensate for bullet drop.
In a pinch POSP optics will work just fine as long as the proper AK or universal mount is used (SVD mounts do NOT slide on from the front and even though they may fit they will not hold zero unless by pure luck)