Looking for info about these vintage Federal HI-POWER 20 Gauge

Hey all, I came across these shells while cleaning an old barn out that I was told has been standing since the prohibition days. Among other items that were clearly antique was a stash of what I assume would have been quite valuable magazine/tabloid type print publications from the JFK assassination in '63, if they had not been soaked in animal urine and feces. I only mention them in the hopes that it might help narrow down the age of these 20 guage slugs. I’ve scrolled through Google results un

Collectible Ammo: Lot of 5 Boxes of Vintage Federal/Winchester

Vintage Federal Hi-Power Shot Shells 20GA Empty Ammo Box (Gold

Where Are All the Specialty Shells?

Federal 3 Magnum 25/20 Gauge Long Range Shot Cup - 20 Shotshells

Federal HI-POWER 28 Gauge - 3/4oz. Shot - 6 Shot Shotshells!! Qty

20ga Rifled Slugs - Federal Hi-Power - 1 Box of 5 Rounds

Tungsten Super Shot - The Evolution of TSS Shotgun Shells

Lot Detail - FEDERAL HIGH POWER 20 GUAGE 2 3/4 MAGNUM SHOTGUN SHELLS

Looking for info about these vintage Federal HI-POWER 20 Gauge

Vintage shells. Safe to shoot? : r/Shotguns

Federal Hi-Power Steel Shot 20 GA, 2 3/4, 4 Shot (1 X 25

Federal Hi-Power Shot Shells 16 and 12 Gauge

Federal Hi Power 12 Ga Plastic Shells Full Box

Buy Slugger High Velocity Rifled Slug for USD 8.99

G2 Research R.I.P. Shotgun 12 Gauge 2-3/4 303 Grain Solid Brass

12 GAUGE SHOTGUN SHELL DECAPPER

Remington 410 Bore Ammo – 5 Rounds of 1/5 oz. Rifled Slug Ammunition - Ammunition Export

Buy Trophy Copper Sabot Slug for USD 21.99