Dan: Like you, I became frustrated over the lack of or inaccurate pellet weight info. Solved the problem by buying a digital scale at Harbor Freight for $17.99 (Cen-Tec brand). This scale is sometimes on sale for $10 or $11.99 and measures in grams, drams, ounces.... From every tin I take a random sample of at least 20 pellets and weigh them, getting a result in grams. I multiply the gram result by 15.4321 then divide by the number of pellets weighed. Any error is less than 5%. I never weigh a tin of pellets - just because the label says 250 or 500 does NOT mean there is and I am not going to count them all. As far as Gamo pellet weight changes - Possibly new molds, new molding contractor, change in alloy, etc. - any number of reasons.