They were offered in 7x57, 7.65x53, 8x57, and 9x57. They are excellent quality rifles as would be expected of Oberndorf. They were produced to offer a lower cost rifle to the public and also to military customers. They were produced using military stepped barrels and usually military floor plates magazine boxes and triggerguards as well as military type tangent sights. Also round bottom pistol grip military type stocks were used (walnut)-made to a sporting length with checkering usually only on the pistol grip, and they can have pear shaped bolt handles or military type. They also have a rear sling swivel of a military type similar to a winchester model 70 supergrade. I own two, one in 8x57s and one in 7.65x53. They are fine rifles and have a rugged feel to them. I shoot the 8x57s and intend on doing some deer hunting with it. There does not seem to be very many available in the U.S. for sale. They don't have the elegance of a model B, M, S, or type A. But they are fine rifles. You are right there does not seem to be too much info on them on the net. Maybe because they do'nt seem to be that common. Overall when you put one up to your shoulder they don't really feel much different than a pre wwI model B and they are less expensive.