308 calibre ???????
are we talking about the same weapons lol.
svd - 7.62mm x 54mmR
slr - 7.62mm x51 nato
Sorry, the area of calibres is a bit complicated and in most books 7.62mm is equated to .308 of an inch calibre.
In fact the 308 Winchester is what the 7.62x51mm NATO round is based on... the civilian calibre can have hotter loads so they are not called the same but in all practical terms they are the same.
The 7.62x54mm Russian rimmed rounds (note it is not a Soviet round... it was invented during the Russian empire period before WWI) is also described as being a 308, even though its original designation was the 3 line rifle... a line being a measurement equivalent to .1 of an inch... so it is often called a .30 calibre... the same as a lot of 7.62mm weapons.
Actually the 7.62x54mm and the 7.62x39mm and the 7.62x25mm rounds the Soviets used in WWII and after are all .311 calibre but they are called 30 calibre or 308, but that is just a mathematical thing as 7.62mm = .308 of an inch.
With the SVD it is interesting because it doesn't have the heavy bolt carrier slamming back and forward like the AK does, yet it still has very serious recoil...
In addition to the universality of the installation of the gun on the technique, a gun of 57 mm caliber itself is universal and can fire on almost any type of target. Infantry, armored vehicles, airplanes, drones, naval targets and the destruction of coastal targets, all this is available to one universal artillery installation.
So imagine the possibility of an improved Su-25 with a 57mm gun on its belly with a 120 or larger round magazine half way down its fuselage.... with perhaps the radar from attack helos and various EO pods with thermal sights and laser range finders for very precise shooting... various gyro sensors that can trigger the gun to fire at the precise aim point needed to hit a ground target 2-3km away or more...
Interesting... and much more fun than stealthy aircraft...