how to test your bbs
 

To prevent damage to your airsoft gun internals (and expensive repars) i recommend testing your bbs by crushing them, here is a video of what i mean,
http://youtu.be/Bo4i_1PRzfM
remember to leave a like

Pliers work better
There's a happy medium between squishy and brittle. If they're too soft you'll get shit accuracy from them deforming during the loading process. Being too soft can even cause them to break apart, just like BBs that are too brittle.