Update to Russianoptics.net - How SVD and AK mounts work

[TX-Zen 287]

I had a bit of free time so I reworked part of the concepts page on russianoptics.net. I took a few more pics and elaborated on how the various clamping mechanisms work for SVD's and AK rifles. I still have a bit more to do but thought you guys might enjoy.

Happy New Year guys

The AK Side Rail - How It Works

Something to note is that since about 1954 the AK actually has had a factory designed method to mount optics - the side rail plate. While not standard issue on every AK it has been effective on the specialized rifles it was added to, and was eventually adopted as standard issue around 1992 in the AK74M series. Considering the AK was first deployed about 1947 you can look back and see that for about 60 of it's 65 year history in Russia the AK has had an effective way to mount optics when the mission required their use. Also of note is that during the past 20 years the ability to use optics has actually been standard right from the factory. Coincidentally you may have noticed that's about the same time frame that optics began to become more and more popular in the West as well.

Another thing to consider is that the side rail design is not an accident, it was designed for a specific purpose and it has proven itself effective for half a century or more in Russian and former Soviet service. Many countries have used the same or similar side rail mounts as a standard way to mount optics; and of course the SVD Dragunov has used it's original optic and side rail for over 40 continuous years with only minor changes during that time.

In contrast to what many believe, the Soviets and Russians continually improved equipment and gear over many decades of service, either to make things easier or cheaper to manufacture on a large scale or to improve performance and reliability. It is interesting to note that of all the things the Soviets and Russians could have chosen to do when it came to an optical solution, they elected to keep the same system in place relatively unchanged, while at the same time continually improving other systems as required. This does not mean the side rail is the perfect solution or the final answer in optics, but it should be an indication that it does work and has been battle proven in numerous conflicts.

The side mount is designed to be removed and returned without the optic losing zero and in practice if the tension is adjusted properly they will do just that and perform as expected. There are a number of clamping mechanisms for how this is accomplished but they generally work the same. They are designed to be slid on from the rear of the receiver, pushed forward and secured by the locking lever... none are designed to slide on from the front of the rail and be pushed towards the back of the receiver. The reason is because under recoil side rail mounts tend to walk forward to the front of the rifle, not backward. By design there is a stop mechanism in the clamping part of the mount...on the SVD mount it's a small bump type rivet near the front and on the AK style clamp it's built into the rear of the mount itself.

Mounting types:

We commonly refer to optics mounts as either AK or SVD type mounts but there are actually many more than that, and they are different based on manufacturer. In reality most Russian optics carry a universal AK/SVD mount as do most BelOMO optics outside the POSP series. This means that most any optic produced by either company can be fitted to SVD's or AK's using a suitable side rail. (Note that many variations exist between different countries and the rails they manufactured, in this case I am specifically referring to Russian/Belarusian designs)

When the term AK mount vs SVD mount comes into play it is usually when talking about the BelOMO POSP series, or the actual PSO-1 Dragunov optic that NPZ produced for the SVD.

One thing to note is that all optics mounts are designed to slide on the rail from the rear of the receiver and are pushed toward the front and then locked into place with the throw lever.

None of them are designed to slide on from the front.

This is because optics tend to walk forward under recoil and an optic slid on the front will eventually lose zero and possibly fall off. This happens because each mount is designed with a stopping rivet or the back of the mount that runs into part of the rail and keeps it from moving forward. When slid on from the front these parts do not connect and there is nothing to prevent the optic from moving forward if the tension from the lever loosens. It is possible to slide SVD mount optics onto AK's rails from the front but it is pure luck if nothing happens to the mount or the zero when being used this way.

Clamping mechanisms simplified

There are really four main types to understand:

1: The original SVD mount (locking lever on top, lever throws and locks forward)

The stop pin to prevent the optic from walking forward is on the front of the mount

SVD mounts will not fit AK rails because the stop pin prevents it from seating on the rail. (Note that the Romanian PSL is an AK pattern rifle but uses an SVD style rail)

2: The SVD style universal mount (locking lever on top, lever throws and locks rearward)

The stop pin to prevent the optic from walking forward is on the rear of the mount

3: The original NPZ and BelOMO style universal AK+SVD mount (lever on the bottom)

NPZ:

80's era NSPU night vision scope

Note that the Universal mount fits AK's and SVD's

Axion Kobra, BelOMO is the original designer of the mount

4: The civilian MTK-83 AK mount (lever on the bottom)

BelOMO makes this mount as well as the one above

RS Regulate has a US made version of the MTK-83

The primary difference between these types is how far forward they will seat on a rail. Remember that SVD optics sit at the front of the longer SVD rail but AK optics sit centered over the shorter AK rail.

With experience you will notice that the clamp pivot mechanism is intended to sit in the center cutout of any given side rail. By that I mean the optic must slide forward on the rail until the clamp can freely open or close and it can't do that if it's not in the correct spot on the rail, which is the center cutout.

By looking at where the clamp pivot mechanism is at you can get a pretty quick idea of what rail it was meant for because of how far or close to the back of the rail it will end up.

NOTE

To further clarify not all optics use a stop pin. Many of the universal SVD mounts have the stop pin but 'regular' AK mounts actually use the back of the clamping mechanism to prevent the optic from sliding forward. You can see some are pins and some are the mount itself.

Examples of side rail mounts using various clamps:

Top Left: BelOMO MTK-83 AK mount (this is what we typically refer to as the AK mount)

Top Right: NPZ universal AK/SVD mount

Bottom Left: Molot AK mount (similar to MTK-83)

Bottom Right: K-VAR AK mount (variation on SVD/universal type mount)

SVD mount top and middle, MTK-83 AK mount bottom:

BelOMO Universal mount (Axion Kobra is similar):

PK01-V and some of the newer BelOMO optics do not have a stop pin or flat edge on the back of the mount to keep them from sliding forward. When mounting they have to be lined up with a center cutout on the AK rail by hand or they will keep sliding forward and come right off from the front. Instead of a stop pin to prevent them from moving forward instead the mechanism is actually in the throw lever itself, when lined up with the center part of the AK rail it acts as a cam when locked and prevents the optic from moving forward.

Variety of AK specific mounts. Note that Obzor, PK-A and PK-AS use the universal style of SVD mount adapted for AK rails:

Zeiss ZFK also uses a variation of the SVD mount:

PSO and POSP optics can swap between SVD mounts, SVD universal style mounts and the MTK-83 mount. Simply remove the four brass screws on the side and the two on top inside and swap mounts. There are two pins that the mount is seated on and often a type of glue to help keep everything secure. A little light tapping with a rubber mallet will break the seal and allow the base to be removed. Sometimes the pins come loose, my experience is that the optic will function correctly without them.

Example of the original SVD clamp and the SVD style universal.

MTK-83 on top, SVD original on bottom

Example of Romanian LPS/TIP2 that has had the SVD base swapped with the MTK-83

Normally the LPS uses an SVD mount

[thebuns1 4,323]

Great info Zen. Thanks for sharing this bro.

[atakacorp 147]

Thank you TX, you helped lots of people, me included .Just got PO 3.5X21P for my VeprX54,after going to your site ,love it .

[Jpanzer 1,265]

Outstanding, as usual!