Cool. 45 ACP ammunition made in 1918. The three rounds in a clip is for the Colt or Smith and Wesson revolver--model of 1917. Having all that ammo in clips is a perfect reason to buy a gun to fit it. Probably corrosive primers,
if you do decide to see if it will still go bang, clean well accordingly.
WWI ended 11/11/18, so your ammo was most likely made during the war.
REM-UMC is the manufacturer. Still in business. "Remington-Union Metallic
Rifle round. Guessing 30-06. Frankford Arsenal? 1937.
Suspect they are reloads---I've never seen a lead bullet/gascheck
military round. Not saying they couldn't exist--there's LOTS of stuff I've