
Based on numismatic standards and the provided reference materials, the official specified weight for a 1943 Jefferson nickel is 5.0 grams. These coins, commonly known as "war nickels" because their metallic composition was altered to conserve nickel for the war effort, were minted to this specific standard.
It is important to note that the United States Mint allows for a slight variance in weight, known as a tolerance. For these silver-alloy nickels, the official tolerance is plus or minus 0.194 grams. Therefore, a newly minted, uncirculated 1943 nickel should weigh between 4.806 grams and 5.194 grams to be considered within the accepted mint specifications.
The actual weight of an individual coin can differ from this range, primarily due to post-minting factors. As indicated in the context, coins that have been in circulation for a long period can weigh less than the lower tolerance limit of 4.806 grams. This reduction in mass is typically the result of wear, where a small amount of the coin's metal has been worn away through handling and use over many decades.


