That said, it sounds like there’s been some estimating going on at your stores when meats are packaged instead of weighing each package.
I would guess that the meat counter staff is printing multiple labels, dividing up the meat, and putting labels on each package without weighing them.
While this likely saves the workers time, as you found, it seems that accuracy is suffering. I would advise taking your concerns to the stores in question. Bring your receipt and packaging labels too if you still have them.
By law, your store must abide by your state’s bureau of weights and measures. These bureaus exist to ensure that measurements are accurate, and also that your store’s weighing devices (scales) are accurate as well. You can do a web search to find your local state’s bureau and contact information.
If you have no luck seeing results after raising the issues of underweight meats at the store level, you can contact your state’s bureau and file a complaint.
In the meantime, when you shop, use the tools available to you in the store to help determine whether or not your meat packages weigh what they’re supposed to.
Scales found in the produce department are handy to use not only for fruits and vegetables, but for packages of meat too. (I often use them to weigh bags of apples or onions. All bags in the bin may be marked “3 pounds,” but I typically find bags that weigh even more. When sold by the bag, get the heaviest bag!)