How much variance in bat weight should you expect?

[HollowMan]

I grabbed the wife's cooking scale, made sure it was calibrated/zeroed by testing with known weights, and measured whatever bats I could find:

Easton Synergy SCN8B 30/20 - weighs 21.7 oz
Easton Synergy SRV4B 31/21 - weighs 23.5 oz
Easton Synergy SCN8B 31/21 - weighs 23.0 oz
Louisville Slugger FP74M 31/19 - weighs 20.2 oz
Easton SSV1B 31/20.5 - weighs 21.6 oz
Worth Mayhem 30/18 - weighs 19.6 oz
Rawlings Rush 30/20 - weighs 20.6 oz