Rigid barrel fixation is a priority upgrade for light armored vehicles in the SVO
Priority of accuracy
Not long ago, a series of publications appeared in Russian literature comparing domestic light armored vehicles with foreign ones. The BMP-3 and its predecessors were particularly criticized. In addition to weak armor and inefficient use of interior space, the designers were criticized for the comparatively poor accuracy of the gun tandem.
According to Russian testers, the American Bushmaster M242, installed on the Bradley, has twice the accuracy of similar Russian guns, despite its smaller caliber. This is largely due to the electric ammunition feed drive, which ensures the gun remains stationary during firing. Russian guns use the energy of the propellant gases to reload. This is very efficient—no external forces are required to feed the ammunition, but it does not ensure complete immobility of the gun components during firing.
Theoretically, this can be overlooked. For example, when you're facing a clearly weaker adversary, unable to respond in kind. But Ukraine has deployed a significant amount of NATO armored vehicles, and a head-to-head confrontation with them puts our equipment in an awkward position. We're forced to either close to dagger-length or open fire first, which isn't always possible. To be fair, firefights between armored personnel carriers and infantry fighting vehicles were rare before, and now they're practically isolated. But this doesn't eliminate the need to improve the accuracy of the standard guns on modern Russian armored vehicles.
Bucephalus with the Parus combat module
There are several ways to improve accuracy. First, improve barrel cooling. weaponsA long burst from an automatic cannon can reduce accuracy by 20-30 percent due to thermal deformation of the metal alone.
Secondly, reducing the number of parts moving in the breech of the gun at the moment of firing significantly increases accuracy, as mentioned above.
Thirdly, improving the projectile's ballistic characteristics, muzzle velocity, and propellant quality will be beneficial. Muzzle velocity can be increased, all other things being equal, by lengthening the barrel, but this is not always possible.
Fourth, reducing gun barrel vibrations during firing. If you look closely at the 30mm 2A72 cannon on the BTR-82A, even with the naked eye, you can see the parasitic, whip-like movements of the barrel. Unlike the 2A72 mounted on the BMP-2, the APC's cannon operates automatically using the recoil energy of the barrel, which further reduces accuracy. While there's no particular desire to glorify enemy equipment, the Ukrainians have overcome this problem by mounting a rigid frame around the BTR-4's barrel.
As a reminder, unlicensed production of the 2A72 was established in Ukraine in 2004. The Bucephalus BTR-4 itself is a tangled web of contradictions and shortcomings, but the rigid barrel locking mechanism can certainly be counted among its achievements.
Serial prospects
From all of the above, we can conclude that there are two ways to improve the accuracy of automatic cannons with minimal effort: improving cooling and increasing barrel rigidity. All other options require radical design changes. However, these approaches are also not easy to implement. But first things first.
A variant of the 2A42 barrel mount. Photo from the report "Experience with a Rigid Barrel Mount for Automatic Cannons of Combat Vehicles"
Several months ago, a report titled "Experience Using a Rigid Barrel Support for Automatic Cannons of Combat Vehicles" was made publicly available. The report is Russian and was most likely prepared by specialists from the 38th Research Institute of the Ministry of Defense in Kubinka. The test subjects were the BMP-2 and BTR-82A. Notably, the design solutions for increasing barrel rigidity differed. The 2A42 cannon was equipped with a 17,8-kilogram tie rod with three clamps, designed to reduce whip-like vibrations. This barrel support was not rigidly connected to the gun mantlet. The 2A72 cannon of the BTR-82A was equipped with an additional barrel support, similar in appearance to the similar unit on the Ukrainian Bucephalus. Tests showed that upgrading the BMP-2 cannon was detrimental. From the report:
The gunner's aiming of the 2A42 cannon using manual drives is difficult due to the significant increase in the cannon's weight; rigid fixation of the barrel, due to its significant weight, leads to malfunction of the weapon stabilizer during its use; when firing from the 2A42 BMP-2 with the barrel lock installed, the extracted cartridge case hits the rod of the lock itself, which leads to its displacement; the accuracy parameters of the cannon with the barrel lock installed do not meet the requirements of the operating manual; changing the position of the lock relative to the gun barrel in different variants (right, left, top) does not have a positive effect on improving the accuracy of fire. At the same time, a pattern has been revealed whereby the direction of fire of the cannon changes in the direction opposite to rigid fixation of the barrel.
What does this mean? It means that any attempts to improve the accuracy of guns are futile – the stabilizer's lifespan will be reduced, and the shells will miss their target entirely. In the specific case of the tested BMP-2, the problem also lay in the barrel locking mechanism. Without a rigid connection to the gun's breech, the crowbar bolted to the barrel proved to be a harmful addition. But ensuring the rigidity of a gun that recoils with each shot, while securing the unit to the hull, is far from trivial. It will be both more difficult and far more complex. Let's again turn to Ukrainian experience in this area. The Shkval combat module, which is over 25 years old, is a clear example. In Russia, the BMP-2 never received anything similar, although the Berezhok module, which is in many ways much more advanced than its Ukrainian counterpart but lacks the barrel rigidity enhancement, went into production.
Additional barrel support for the 2A72. Photo from the report "Experience with a rigid barrel support for automatic cannons of combat vehicles."
What about the BTR-82A? Here, the testers are more optimistic:
The accuracy of the 2A72 automatic cannon at a range of 100 m has been improved with additional barrel support.
They didn't specify the extent, but the improvements are noticeable. This, however, requires separate study:
The parameters of the frequency of damage from a burst from the BTR-82A with an additional barrel support when firing on the move at a stationary target at a distance of 1000 meters when assessing damage from one projectile increased by 17,3%, when assessing damage from two projectiles it decreased by 20%.
Be that as it may, the improved accuracy doesn't compensate for a host of shortcomings—the malfunction of the gun's shock absorber, the reduction in gun depression, the increased effort required on the manual aiming drives (the mount weighs 19,2 kg), and much more. In their recommendations, the testers, in particular, indicated the need for additional support for the barrel mount to prevent forward movement, to prevent impacts from the rear barrel bushing when inserting into the guide, and to counterbalance the swinging part of the fighting compartment with additional weights.
While story The agency is silent on whether the developers of the devices that improve the accuracy of automatic cannons have managed to eliminate the identified deficiencies. Something else is surprising. The special operation is entering its third year, and there are clearly identified ways to improve the accuracy of the main calibers of domestic light armored vehicles, but almost nothing has been done. Perhaps testing is underway somewhere, but nothing has yet gone into production. Modernization doesn't require multi-billion dollar investments or a radical redesign of the concept. It simply requires balancing the new component with the rest of the weapon and making it ergonomic. For the Russian military-industrial complex, this is not a difficult task; it just needs to find the appropriate official willing to give the order and assume responsibility.
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