Tommy,
From the shape of the tang button, I suspect it is a "cocker/de-cocker" instead of a "selector". The function is close to the same but is considered to be safer. The rifle cannot fire unless it is cocked, on a "thumb cocking" drilling. What is unclear is the function of the grip safety when firing the rifle. A "thumb cocking" drilling would not typically need a safety to be "off" to fire but holding this one in the normal manner would cause the safety to be "off". I can't know for sure if it is a "thumb cocker" from the photo alone. If I had it "in hand" I could tell whether it is or not by "feel". If pushing the button forward cocks the rifle you can feel the extra effort required to overcome the spring tension. When you post the additional photos be sure to include all the markings and be sure we have clear images. You can't find a "6.4x58 1/2" cartridge because these markings are not the nominal designation of the cartridge. Rather, the 6.4 is the bore (not groove or bullet) diameter. Likewise, the 58 1/2 is the longest case that will chamber but says nothing about the shape of the case. These marks may indeed fit with the 6.5x 58R Sauer. There are a couple other 6.5x 58s that these proof marks would fit but both are unlikely to be chambered in a drilling. The bore diameter should be checked because the 6.5x58R Sauer usually uses a bullet smaller than the current standard .264" diameter. My own 6.5x58R Sauer uses a .260" bullet, which seems to be the most common diameter. I have read of one drilling that used .264" bullets so you might be lucky and not have to resize .264" bullets or use undersize .257" bullets. Cases can also be problematic but once you have enough, you don't have to worry about them anymore.
Mike
Last edited by Der Ami; 02/10/22 10:13 AM.
