Some people have said you can bounce them on a table and go for the highest pitch sound at impact. Others say put them in a glass of water, if it floats its bad, if it sinks its good.......... I think if you pour the blood of 3 chickens on the kitchen floor in the shape of an ahnk and chew on a bats eyeball, you will have the vision to see which one is the best out of a box.
Seriously though, if you press them in a vise, they are all pretty good. And more consistant from tip to tip. I think the problem in manufacturing the past few years is a pressing step. Either they have lessened or eliminated pressing the tip while making it. Thats just my thoughts.
Chuck