1PN51 Soviet Night Vision

An excellent reference for 1PN51 is found HERE on Dragunov.net

Again many thanks to Herr Berg for the link, and to Brian Wilhelm on his writeup which I posted on the night vision title page

1PN51 is by far the rarest Soviet military night vision optic in the US and has always been tough to find.

I've never actively pursued acquiring a 1PN51 before now, partly because of the rarity and partly because I have been really busy collecting other daylight optics. I've had a couple chances in the past but declined for one reason or another, however in 2017 I found a really good deal and decided to take a chance.

There is always a risk when buying any dated Russian night vision optic because they don't have an unlimited service life and you never really know the quality until you get it, but in this case it worked out quite well. The unit I have came complete with a full transit case, all accessories, and lights up very nicely. It needs a bit of a focus adjustment but is still quite usable out to 300m or so. The most I will realistically use it for is hog hunting in Texas and it will be very suitable for that.

My optic is also not serialized to the transit case and the paperwork is not serialized either. This is not uncommon with 1PN51 in particular, but somewhat atypical for optics with the transit case and paperwork which tend to be serialized when found in such a complete state.

Despite being 20+ years old 1PN51 is a solid Gen 2 device and really out performs any civilian Gen 2 that I have personally seen. There is something to be said for military grade optics vs civilian and 1PN51 demonstrates this quite well. It performs remarkably better than 1PN34 or 1PN58 and has none of the classic fish eye effect of the Gen 1 designs.

As I have mentioned on the 1PN93 page I am having a tough time deciding which optic is overall more effective in all the lighting conditions I have seen in testing. PN6K-5 is the hands down winner, but between PN-6K and 1PN51 it is not so clear cut

1PN51 has the best close range and indoor resolution that I have personally seen on a Soviet or Russian night vision optic. It can handle distances measured in inches vs meters for the others. While my particular example needs a little adjustment to the focus the sensitivity is quite good and it can see a long way. In testing 1PN51 seems to perform best at night in open spaces compared to PN-6K which seems to do a bit better in urban environments with more background lighting

On the NDM86 with digital flora Chamelion chest rig and the MP4-20 spotter scope

Transit case is not serialized to this optic but does have the full kit including ballistic cams still covered in cosmoline

1PN51 is smaller than the older NSPU optics but still not small. Compared to 1PN114 they are similar but 1PN114 has better optical quality and the nifty feature of being a daylight and night vision optic. Weight is 72 ounces for 1PN51 and 63 for PN6K-5

The desiccant cartridge is visible below the on/off dial. The purpose is to give a visual indication if the tube is wet or dry which could render the scope unusable if too wet, as well as acting as a desiccant to keep the tube dry

МЕХАНИ3М ВЫВЕРКИ ПО НАПРАВЛЕНИЮ ПО ВЫСОТЕ
Mechanism of correction (Height and Windage)
Each knob has three screws that are loosened in order to move the reticule for zeroing
Shown here with AKS-74UN cam (AKSU with side rail)

BDC Cam replacement / Adjusting elevation for zero
Remove the three screws to pull the dial off and replace the cam. You loosen the screws in order to rotate the dial and adjust for windage and elevation similar to how a PSO-1 works.

The daylight lens cover
It can be adjusted open or closed. Fully remove for night time shooting
1PN51 has a fairly sensitive autogate feature and will shut off quickly if overloaded, but you can move the lens filter one click at a time to get the best picture for daylight shooting. It returns to normal operation really quickly after the auto shutdown happens.
Because of this design I have found 1PN51 to be a bit more resistant to harsh lighting conditions in the daytime compared to PN-6K and PN6K-5

The irons are not blocked by 1PN51, which is typical for the SVD compatible optics (and Soviet night vision in general)

The brightness control - On/Off. The reticule brightness is adjusted by the dial, but the night vision sensitivity itself is either on or off, if you move the dial away from the off position. It is not more or less sensitive depending on the dial. Sensitivity is partially controlled by the day light filter which has a lever to open or close the daylight iris, however at night without the lens cover the optic is always either on or off. The dial allows the reticule to be brighter or dimmer and it is sometimes necessary to adjust the reticule brightness

On the AK105

On the 1988 Ishmash AKS-74N clone

With Dead Air Wolverine PBS-1 suppressor

Two CR2 batteries will provide the 6 volts necessary but this may not be stable under recoil. I was able to zero the optic during the day using these two CR2s and it held up just fine, but you may experience it differently
Original dry cell battery on the right. These are very rarely able to hold a charge but can sometimes be rebuilt.

My set came with a civilian Russian battery apparently designed exactly for the battery compartment on the 1PN51 (and 1PN58)

On the NDM86
It seems like an ungainly and awkward optic but it is rather manageable when you actually shoot with it. At almost 4 pounds it's certainly heavy but from a fixed position it's not the end of the world. I sincerely doubt I would enjoy movement to contact using the SVD and 1PN51, but it could be worse I suppose

Sighting in with OVU-1. 1PN51 is actually one of the sharpest Russian optics at close range / inside buildings that I have seen yet. It does remarkably well even at 15 feet (5m) and here you can see that the OVU-1 body is quite visible even though it is only 2 feet away at the muzzle

Night Vision Testing

Distance to the treeline is about 1700 meters, or 1 mile. There were clear skies and about a half moon. This was a rural setting with no urban lighting

Compare a similar view on the same night with 1PN114 / PN6K-5

Urban setting. Distance is about 100 yards with no lens cover

Distance to the vehicle is about 200 yards. This particular 1PN51 could use a bit of a focus adjustment. I have it cranked all the way and it still needs a bit more, but still functional