I will not be mistaken if I assume that everyone who is "shifted", in the good sense of the word, on firearms with non-standard solutions in the design, know about the Croatian large-caliber rifle RT-20, in which the exorbitant recoil when firing is extinguished with the help of jet exhaust of powder gases from behind weapons. For grenade launchers, such a system is quite familiar, but for a large-caliber rifle it is very rare. However, the rarity does not mean that this is the only sample with such an original design. As I have often said, everything that "has no analogues" has its progenitors in the late nineteenth - early twentieth century. In our case, everything is somewhat different, although on the other hand the Croats did not claim the absolute uniqueness of their weapons. The "relative" RT-20 was found in 1942 among the Swedish anti-tank rifles.
PTR with a similar method of damping recoil appeared due to the active development of means to combat light tanks and lightly armored vehicles in Sweden. The Carl Gustav company developed a truly original sample of weapons and ammunition for it, and the anti-tank gun itself was very light weight, about 2-3 times lighter than its compatriots, had quite tolerable recoil and at the same time could boast of penetrating 40 millimeters of armor at a distance of 100 meters. The most interesting thing is that the weapon did not even have a bipod as such; if it was necessary to rest on the ground, a curved tube was put on the shoulder rest, which served as a bipod. Well, now the most important thing is the ammunition of the weapon.
A cartridge with the metric designation 20x180R was specially developed for this anti-tank rifle. Despite the fact that the ammunition had a fairly large powder charge, not all of it was used to disperse the bullet along the barrel of the weapon, a significant part of it simply flew into the air when fired, to counteract the exorbitant recoil that could have been when using the same cartridge in a closed the system will simply break the bones of the shooter. Despite the fact that the powder charge is not fully used, a bullet weighing 150 grams accelerated to a speed of 800 meters per second. A lighter bullet, weighing 108 grams, accelerated to 950 meters per second. The results are quite good, and with a reasonable recoil of the weapon, they are just wonderful.
As mentioned above, recoil damping when firing from the PVG M / 42 anti-tank rifle is carried out using a jet stream of powder gases emitted from the rear of the weapon. In the Croatian RT-20 large-caliber rifle, powder gases are removed from the barrel through several holes into a separate tube. In the PVG M / 42 anti-tank rifle, everything is done at the same time and is simpler and more difficult. The simplicity lies in the fact that the jet exhaust is carried out immediately behind the barrel, without separate parts, which significantly reduced the weight of the weapon. The difficulty is that in order to accomplish this, it was necessary to make a sleeve with a bottom, which is knocked out by powder gases. Thus, the cost of the already expensive ammunition increased significantly, and the quality of these cartridges had to be at the highest level so that the bottom of the case would fly out exactly when it was required.
The PVG M / 42 anti-tank rifle itself is a very simple sample, consisting of a barrel, a simple trigger mechanism and a bolt that opens the chamber when turning. The weapon is single-shot, which creates certain inconveniences when reloading due to the location of the shoulder rest. So, in order to reload the anti-tank rifle, it was necessary to remove it from the shoulder, or wait until the second fighter crawled up to reload and crawl away before firing. The loader had to crawl a lot and quickly, since the jet stream escaping from the back of the weapon could teach him to move quickly. But, oddly enough, there were no cases when someone preferred to learn to crawl with such a tough motivator. In addition, one should not forget that, along with the jet, the bottom of the cartridge case flew out, which, although it flew close, could also injure a gaping soldier.
The weight of the PVG M / 42 anti-tank rifle was 11 kilograms with a length of 1450 millimeters, so the weapon could well be carried by one person, for which a carrying handle was welded on top. The barrel length of the anti-tank rifle was equal to 1114 millimeters, the effective range of use was up to 300 meters, however, everything depended on the target that had to be hit.
Many consider this PTR as an unfortunate model, and a kind of mistake. You cannot argue with many arguments, in 1942 the time of anti-tank rifles was already coming to an end and their effectiveness was inexorably falling to zero. On the other hand, in addition to tanks, there were other armored vehicles, fortified firing points, in the end, light tanks, at which anti-tank weapons were fired very effectively. Do not forget about the grenade launchers, which continued the PTR business, and this sample has a certain similarity with them. In other words, this anti-tank rifle gave invaluable experience to designers in the fight against recoil in recoilless systems, and this is not enough. And the PTR itself received a good distribution, since 3219 weapons were produced.