I have seen multiple times from multiple places from multiple people that you have to make sure the tang is free floating on your Savage. And if you hear something often enough it becomes truth and conventional wisdom.

1. Is this a Savage thing or can other brands of actions also benefit from this?
2. What are the physics behind why this is?

All of mine are free floated and they all shoot really well so I don't want to put them in tight, if it's not broken don't fix it. Right?