[wulfir]

Here's a text by a user from a Swedish language forum on the Strv 103:

Stridsvagn 103 in service
As demonstrated above, the strv 103 was developed with the same kind of requirements as a turreted tank. It should hopefully not come as a surprise that when it was taken into service in the armored brigades, it filled the exact same role as a turreted tank. In the 1970's, the Swedish army's modern tanks (the strv 103 and the Centurion) were organized in seven armored brigades, plus a few independent mechanized battalions. The armored brigades was the army's spearhead - there were dozens of infantry brigades, but the few armored ones were the ones that could really conduct an offensive operation in depth against a mechanized enemy. If you take a look at a map, you might be wondering where the Swedish army imagined it was going to conduct a mechanized offensive - while most of the country was east of the Iron Curtain, it was entirely surrounded by water and friendly countries, and the army had no landing craft capable of crossing the Baltic sea. Of course, the answer is the one that was hinted at above: the armored brigades were for counter-attacking beachheads, airborne landings or even an enemy that had established a foothold in the country. The infantry brigades were well suited to defending and delaying, but were only really capable of attacking in what was termed "covered terrain" (i.e. mostly forests and urban areas). Open country was tank country, and consequently the armored brigades had their initial positions in strategically important open areas. Three of the seven armored brigades had their initial positions in the provinces of Skåne and Blekinge, at the very southern tip of the country - mostly flat and open terrain, and only a few hours from East Germany and Poland by ship. One was stationed on the island of Gotland (also flat and open terrain, and not a big island at all), two in the densely populated and strategically important Stockholm and lake Mälaren area (one in Strängnäs, south of the lake, and one in Enköping, north of the lake) and finally one in Skövde on the big plains in the southwestern part of the country where a lot of important air force bases were located, and where it could easily reach the important harbor in Gothenburg. (5)

In the 1970's, two of the brigades in Skåne and the one in Skövde were equipped with strv 103's; the rest had Centurions. Strategically, it didn't matter which tank the brigade had - it was expected to fill the same role and had almost exactly the same organization and equipment (other than the tanks themselves). Tactically, there were a few differences, but they weren't huge. The same field manuals were used for both Centurion and strv 103 formations down to platoon level (one platoon was three tanks) - only the field manual intended for individual tank crews differed. The tank gunnery field manual from 1974 (which was also the same for both Centurions and strv 103's), only a few very specific points called attention to the difference in tactical usage between the two. More specifically: the manual stated that firing on the move was to be avoided, even in a tank with gun stabilization like the Centurion. In a Centurion, firing on the move was permitted at distances up to 800 meters, and it was only to be done if there was a very good reason for doing it - one example given was to attempt to suppress an ATGM crew that had just fired before it could reload. In the strv 103, firing on the move was only permitted at distances up to 200 meters, which is basically knife fighting range in a tank. Instead, the field manual heavily emphasized the need to get the first hit in. Firing first and hitting with the first round fired was an enormous advantage, and in big bold letters the manual stated that in tank duels, the tank that got the first hit was four times more likely to win than the tank that didn't. Furthermore, the manual went on to say that the enemy was expected to have many more AFV's than the Swedish side could expect to have, and wasting ammunition was not acceptable. In other words, the gunnery doctrine was firmly centered on well-aimed fire and hitting with the first round. The strv 103's inability to fire on the move was no big disadvantage in light of this. (6)


Conclusion
The stridsvagn 103 was conceived as a tank, developed in response to a demand for a tank, and used as a tank. It was not a tank destroyer or a "defensive" vehicle. Repeated trials both in Sweden and abroad showed that in most cases it was insignificantly slower to react to a target appearing on its side than a turreted tank was. In fact, due to its duplicated controls (the commander could override the gunner/driver's controls and, for example, point the tank at a target that he could see through his rotating cupola but the gunner/driver hadn't spotted) it could even be faster to react than a turreted tank without similar functionality - the turreted tank's commander would have to talk the gunner into finding the target. The inability to fire on the move was not considered a significant disadvantage considering the Swedish gunnery doctrine at the time.

The strv 103 proved to be an evolutionary dead end, however. Stabilization technology improved rapidly during the 1970's, especially with the introduction of gun-follows-sight technology, and the next generation of Western MBT's that appeared around 1980 were only slightly less accurate on the move than they were at a standstill. The 103's heavily sloped - but not all that thick - front armor which offered good protection against 1960's armor-piercing rounds was completely insufficient against newer 1970's "long rod" penetrators. It was a very innovative and very Swedish think-outside-the-box solution in 1960, but it should have been replaced around 1980-1985 - the original requirements called for a technical lifetime of 15 years.

The full thing (in English) can be found here (with references):

http://forum.skalman.nu/viewtopic.php?t=46219