Thanks in advance. I came across a WESTERN 6-17 head stamp that appears to be a 6-5-3006. It does not look like a hand load. It has a copper primer. The bullet is non magnetic and has a streamlined point.
Picture is worth a thousand words.
Sounds like a factory made .256 Newton made by Newton Arms Co. They used .30-06 cases with this headstamp. Also, check the bullet tip with a magnet, since original loads are loaded with a wire protected soft point.