Small arms ingenuity was an area that the Soviets held something of an advantage in over their German counterpart in the decade leading up to World War 2. One keen example of this was in the AVS36 - Avtomaticheskaia Vintovka Simonova - designed by S.G. Simonov - a self-loading service rifle with semi-automatic fire, giving the standard infantryman a distinct advantage in sustained fire over that of those still using bolt-action rifles. A soldier with an automatic rifle and healthy ammunition count made for a more efficient fighting unit and, in collection with other battlefield implements, provided much in the way of tactical flexibility. However, the AVS36 was a complex beast that did not lend itself well to the rigors of fighting - it proved prone to failure, particularly of her internal moving parts, when firing the powerful 7.62x54R Russian cartridge. Additionally, general issues with dirt and dust making their way inside further complicated operation. As such, the AVS36 was a short-lived "success" that eventually gave way to the SVT-38 series designed by Tokarev.
The SVT-38 (Samozariadnyia Vintovka Tokareva) was brought online in 1938 and immediately replaced the AVS36 series in Red Army service. The weapon system was from the mind of F.V. Tokarev who also delivered the useful TT series of pistols in the early 1930s. The SVT-38 featured a gas-operated firing action with a locking block cammed downwards against a cut recess found on the base of the receiver. The stock was a two-piece unit while the barrel was capped with a six-baffled muzzle brake to help contend with recoil. A ten-round detachable magazine was fitted underneath the receiver, ahead of the trigger unit and the forward wooden handguard was complimented by a sheet steel covering over the barrel to protect the firer's aiming hand. A cleaning rod was rather unusually affixed to the right side of the buttstock.
However, despite being the "newer" of the two designs, the SVT-38 was nary an improvement over the AVS36 series for it suffered from the same fragile nature of its forerunner. The fragility stemmed from a design attempt to keep the new rifle as light as possible and this, unfortunately, led to its inherently powerful firing action (and subsequent recoil) literally breaking the internal components apart. Additionally, as the AVS36 before it, SVT-38 components also suffered from the general rigors of everyday combat that included exposure to dust, dirt, debris and generally accepted abuse. In 1941, the six-baffled muzzle brake was refitted with a two-baffled design to help offset some of the recoil and muzzle blast while several were also modified with mounts for the fitting of scopes for the sniper role. Regardles, the SVT-38 was a limited improvement and would only see production into 1940 before being replace by the similarly-minded SVT-40.
The SVT-40 sported a heavy wood frame (single banded as opposed to double in the SVT-38) with a protruding metal barrel system, integrated ergonomic grip and attached buttstock. The wooden forend, shortened on the SVT-40, was slotted along the sides for a better forward grip and there were four horizontal vents cut into the upper forward portions for heat dissipation of the barrel. Circular venting on a sheet metal covering was wrapped around the barrel further ahead of the wooden forend. The barrel was capped by a six-baffled muzzle brake and a forward sight post was visible for accurized fire. The receiver held all the major working internal components, which were essentially the same as in the SVT-38 series. The curved trigger sat within an oblong trigger guard and the 10-round detachable magazine was fitted just ahead. Spent cartridges were ejected from the right side of the body. A flip-up rear sight was set ahead of the magazine feed along the top of the receiver. The cleaning rod was now relocated to a more traditional placement underneath the barrel.
At its core, the SVT-40 was nothing more than the SVT-38 with a reinforced structure to help make for improved robustness and reliability in-the-field. The new gun was something of an improvement over the SVT-38 save for the fact that the same recoil/muzzle blast issue plaguing the SVT-38 (and the AVS36 before it) when firing the 7.62mm cartridge was still apparent. The six-baffled muzzle brake was updated to a two-baffled design though it is of some debate whether this installation helped much in practice. Regardless, the SVT-40 was issued in around 1.6 million production examples and some were even fitted with telescopic sights for snipers. The repeating action of such a system no doubt lent itself well in the role, allowing the shooter to keep his eye and weapon trained on a hapless enemy.
Another SVT-40 development was an attempt to produce a full-automatic model. This variant was given the designation of "AVT-40" but these systems failed to provide much in the way of success, leading to very low production figures. Similarly, the "SKT-40" was conceived of as a carbine form of the base SVT-40 rifle, being shorter in length for improved portability. These were either "new-build" models straight from Soviet factories or merely conversions exercised directly from original production SVT-40s. At any rate, these proved rather wicked to fire and were thusly produced in very low numbers.
The SVT-40 saw production until the end of hostilities in 1945 though, despite their usefulness, the weapon would never reach the millions of Red Army soldiers in the required numbers - especially when compared to the similar-in-scope American M1 Garand self-loading rifles, these reaching production figures of about 6 million units. Nevertheless, the SVT series rewrote portions of Soviet infantry tactics as the war progressed, at least whenever they could be fielded in any substantial numbers. SVT-40s were usually issued to non-commissioned officers of the Red Army as well as trained marskmen and the fabled Soviet Marine units. The rifle also went on to influence Soviet post-war automatic firearms designs during the Cold War, a period that ultimately gave rise to the world-renown AK-47 assault rifle family by Kalashnikov. It is also believed that a few facets of the SVT series directly influenced the German design of the wartime MP 43 assault rifle as well - regarded as the first modern assault rifle.
Germany invaded the Soviet Union in 1941 and found the need for a similar self-loading, semi-automatic combat rifle to help offset their bolt-action units. The Gew 41 was developed in response but these proved very limiting in their scope and were released in equally limited numbers. It was only after the German Army encountered the Soviet SVT-38 and SVT-40 models in combat that they advanced their own needs using captured reengineered examples to create the improved Gew 43 series. The Gew 43 served well and was issued n sniper forms but never reached the production levels required of the German Army. Captured SVT-38 and SVT-40 rifles were also reconstituted back into German Army service, whenever possible (and as 7.62mm ammunition supplies allowed) under the respective designations of Selbstladegewehr 258(r) and Selbstladegewehr 259(r), such was the value - and shortage - of capable automatic weapons at this point in the war.
The SVT-40 was also utilized by the Finns as well as North Korea and China.