John,
One of my dad’s hunting partners has a similar story to yours. He was a farm boy who inherited his dad’s M721 topped with a 4x rimfire scope. He handloaded with his fathers old equipment and used whatever primers, powder, brass, and bullets—as long as they were 180 grains—he could find. He would hunt with that mixture of loads, and over the years killed more elk than any other guy in the group.
Back then party hunting was common, and if one or two of the party were lucky enough to draw an uncommon cow tag, the standing policy among the entire group was to "shoot the first cow you see!".
In the 60's and early 70's there was a fraction of the elk in Colorado as there are today, and for a party of four to all fill their elk tags didn't happen very often.
