I've composed a couple of posts worth of deathless prose regarding
canned meat and managed to accidentally delete them, so maybe I should
let well enough alone. However, that would be more prudent than I tend
to be.
I've never canned meat (hundreds of quarts of veggies though), but my
mother said her family did. They were doing it in the 1920s and 30s,
probably without a pressure canner (though they began canning
with?pressure fairly early on).
Mom said that the big advantage was having a near-instant meal if they
had all been in the field all day or if unexpected guests stopped by.
They butchered, of course, in winter, but ate the meat mostly in
summer. I don't think shelf life was a huge concern -- and no one
died.