Hello,

±5% seems a reasonable approximation for weight indication, when accounting for the wear and tear of circulation. But for a coin with little or no wear, a low weight would be a cautionary signal.

PCSG uses 26.4g as reference weight. Using a range of 26.5g - 26.9g, the average weight would be 26.7g. ±5% would be ±1.3_{35}g with really only one significant digit after the decimal place. This would place the coin at the low acceptable range of 25.4g - 28.0 (25.3_{65}g-28.0_{35}g).

With the suspicious reeding and low weight for a lightly worn coin, these combined indications would seem to reinforce a conclusion of a problem coin. At this point, check the diameter and rim thickness to check for disguised weight from over-sized dimensions. Specific gravity measurement should also confirm if composition is close to a 90-10 silver-copper alloy.

Tom G.