I’m not sure that’s a Hornady round… That too was my first thought, then I remembered that Winchester had a small arms line etc that had the head stamp of an H for many years and they were in production at that time. Hornady didn’t start until 1949 or thereabouts, but Winchester was banging out the “Henry” rifle in mid to late 1850's??, (named after B. Tyler Henry the designer)…the company started as the New Haven Arms Company….all ammo produced by them was marked “H”. The gun did well so the company became Winchester and eventually the Henry became the model 66. That gun and their center fire ammo was such a success for them and was used by many…Winchester became an actual company in 1866, but I believe the New Arms co. started a decade earlier give or take a couple years. They continued to mark the center fire ammo with an H up until somewhat modern times I believe. I haven’t used Winchester .22 in over 20 years and I seem to remember the H on some of the cartridges then?! Living in Minnesota for so many years, Federal ammo was a major go to, produced locally, dependable and cheap! So the dating of site with the look of that casing and the H leads me to believe it’s a Winchester round.