I've found a bit more here, IMHO much more informative then the one on RG. Russians call "god of war" artillery ;-)
Despite the fact that the 26th International Exhibition of Arms and Defense Technologies “Eurosatory-2018” ended in Paris three days ago, the news flow about the promising weapons samples announced on it continues to be actively disseminated and discussed in military analytical blogs and on other platforms of the masses -media, attracting an increasing number of fans and specialists in the field of armored vehicles, navy, artillery and combat aircraft. One of such samples was a demonstrator of a 155-mm high-explosive fragmentation projectile with a rocket-ramjet engine, represented by an open-type solid propellant gas generator. The product called "155 mm Solid Fuel RamJet", developed by the Norwegian-Finnish company "Nammo",
Obviously, the creation of this project by Nammo specialists was driven by the realization that the work on designing a hybrid rocket launcher and a one-component rocket engine for the prototype of the British Supersonic Car supersonic car is only a one-time commercial deal that is incapable of giving neither significant economic growth of the company as a whole, nor further strengthening in the arms market in particular. After all, the project "Bloodhound SSC" provides mainly for obtaining research experience in the field of motion of ground-based supersonic objects. Another thing - artillery shells with a ramjet engine, capable of providing their operators with a mass of tactical "buns" in modern theater of operations against the enemy, using conventional high-explosive or active-rocket projectiles. Such products really can bring real success to a small, little-known company.
It is noteworthy that even in the distant 50s and 60s. Twentieth century, Soviet specialists carefully worked out the design and principle of action of direct-flow air-projectiles for the M-24 and BM-21 “Grad” salvo systems in the hope of significantly increasing the range of the MLRS to achieve complete domination in theaters during the exchange of artillery strikes with adversary, but the queue at that time did not reach the implementation of such developments “in the gland”, because at that time there was experience in the manufacture and refinement of only large liquid ramjet engines, designed to For example, for the first intercontinental supersonic KR 4K80 “Storm”, the project of which was closed due to the low low efficiency of the RD-012U ramjet ramjet and the impossibility of 100% overcoming existing American missile defense systems amid 5, 5 times faster MBR 8K71 (R-7) and 8K74 (R-7A). However, scientific and technological progress led to the appearance in the mid-60s. The Circle anti-aircraft missile complex, the basis of which was a more compact than the Burya cruise missile, the 3M8 missile, equipped with a ramjet with a single air intake. It is this air duct design that will become the main one in the development of promising solid-fuel rocket-direct-flow projectiles.
The active work of the specialists of the Tula “Scientific and Production Association“ Splav ”on the creation of a ramjet / RPD for missile systems of volley fire was announced in the 14th year by the representative of the association Igor Ivanov. After just three years, in August 2017, within the framework of the Army-2017 military-technical forum, a demonstrator of a standard 152-mm projectile with a ramjet engine for the Msta-S self-propelled missile sited at the stand of the Baltic State Technical University "Coalition-SV", as well as towed howitzers "Msta-B" and "Hyacinth-B", which indicates the conduct of work in two "branches" at once: for both the barrel and rocket artillery, which is in service with the Russian army. So the Norwegians with their rocket-ramjet projectiles "155 mm Solid Fuel RamJet" can hardly be called pioneers in this direction,
The demonstrator of the Russian artillery projectile with a forward ramjet, unfortunately, is currently represented only by a mockup.
It is worth noting that if the standard ZOF61 active-rocket shells for the Msta-S self-propelled gun (gun 2A64M2) and ZOF44 for the Pion (gun 2A44) can only achieve a 15% and 23% increase in firing range compared to conventional high-explosive 152-mm ZOF64 and 203-mm ZOF43, the new direct-flow projectiles increase this figure either by 80% or more than 2 times (depending on the type, quantity and intensity of solid fuel gas generator in the combustion chamber ramjet / RPD). In particular, our specialists say that the equipment of a 152- / 203-mm projectile ramjet or rocket-propulsion engine of the head or bottom type will increase the range to more than 70 km, which will already become a record figure for these calibers. Meanwhile, the “head” configuration (front engine location) raises some doubts about a 2-fold increase in range, because in this case there is simply no place to place a large and “long-playing” fuel charge on the gas generator. Such an arrangement of the engine will increase the range of the projectile, but only 1.5-1.7 times, or the use of liquid fuel supplied from the tanks built into the body of the projectile will be required.
The most optimal variant is the “bottom” configuration of the placement of the rocket-ramjet engine with a large charge of solid or pasty fuel, which will make these figures (70-80 km) more realistic. The engine will start a few seconds after the gun leaves the cannon with an oncoming air flow and maintain a high flight speed of the artillery projectile for a long time, at a level of 3–3.5M, increasing the flight range and, accordingly, kinetic energy when a remote ground object is hit. There is also a negative point in the presence of a ramjet / RPD projectile: the inevitable decrease in the mass of explosives due to the volume allotted to the central body, the duct, the charge of solid fuel, the gas generator and the combustion chamber.
However, this problem will be partially compensated due to the small circular deviation of the projectile (within 5 m), achieved due to the presence of a control system represented by small-sized nasal aerodynamic control wheels, and high kinetic energy at the moment of hitting the target. Another advantage of such ammunition will be a reduction in the likelihood of interception by enemy missile defense systems such as the Israeli Iron Dome anti-missile system, the British Land Ceptor air defense system, or the German 6-module anti-aircraft artillery complex MANTIS: the missile defense capability is increased due to the high speed of the projectile on the final leg of the flight, which complicates the process of capturing radar / opto-electronic guidance stations, leaving the calculation a minimum time.
According to the well-known military expert Joseph Trevetik, representatives of the US armed forces instantly showed interest in the Norwegian 155 mm Solid Fuel RamJet. This is not surprising, since at a similar or slightly higher cost in comparison with the M982 “Excalibur” shtatovskim projectile, the Norwegian air-projectile projectile will provide a 50–60% range increase from 40 to 60–70 km (when used with M777 howitzers M109A6). When used from guns longer than 50 calibers, the range can increase to 85–90 km. Trevetik claims that such shells can provide a ton of tactical advantages to the US Marine Corps in case of an escalation of large-scale conflict in the western part of the Asia-Pacific region,
For example, in the event of a conflict with Beijing, the 155-mm howitzer M777 with old OFS and even Excaliburs, delivered to the islands by LCAC air-cushion boats, will not be able to provide artillery support to marines advancing deep into the island network, while “155- mm Solid Fuel RamJet "will provide this opportunity. Of course, Joseph Trevetik did not take into account such circumstances as the Chinese fortified areas already erected on the islands, covered by the HQ-9B air defense system and anti-ship complexes YJ-12B, but from the point of view of the capabilities of the artillery, he is completely right.
Direct impact air projectiles will have a greater impact on the course of a possible large-scale conflict in the European theater of military operations, especially in the Suvalki corridor (the area between Belarus and the Kaliningrad region). In the event of a collision between the Russian Armed Forces and the NATO Joint Armed Forces at this site, all of our artillery units stationed in the Kaliningrad region will be diverted to counter-battery work in the Polish and Lithuanian operational areas, while the main item on the Russian and Belarusian gunners task list will be to provide support motorized rifle and tank divisions that keep Suvalki corridor under control to save Kaliningrad. The length of this “corridor” is just 65 km, which means that it can only be covered by new “straight-through” artillery shells, announced at the Army 2017 forum, because spending hundreds of expensive strategic Calibers and tactical Ovodov-M for this purpose is not the best idea. But won't it happen that the Norwegian project from Nammo, backed up by billions of Pentagon injections, will enter the stage of large-scale production faster than our samples? This perspective is really alarming.