Looking at Eisenhower dollars on ebay, I'm seeing 40% silver for 1971 Ike dollars. I'm guessing a '76 would be the same content. They're very nice! You're fanned!
The only Ike dollars with 40% silver 60% Cu-Ni content were ones made at the San Franscisco mint for proof sets. And furthermore, not all proof sets are silver as they also made proof Clad sets (Clad is the cupro nickel composition of all Ikes)
They are not called "proof clad sets" they are just called uncirculated set!!-------the word "clad" has never even entered the picture on a us mint uncirculated set!!!---& furthermore, silver proof sets are made of 90% silver!---not 40%-not 60%---eisenhower was only made from 1971-1978. he is not in the silver proof or uncirculated sets @ all---the kennady half dollar is in them! all u.s. coins are made up of any of the following:::zinc--copper--nickle--manganese---or silver. nothing else is used in any coin minted by the u.s.--and this 1976 coin is made up of 40% silver!!!---and its worth @ todays prices is $12.64