Silverware - Borer after Scattering

The following question was sent by one of the Chabura to Rav Ostroff:

I believe I am correct that if silverware is "thrown" on to the table, I can take what I want even if not l'alter. If yes what is the source for this?

Rav Ostroff replied:

Rav Moshe Feinstein in Igros Moshe, OC Vol. IV Siman 74 (Borer Question 11), based on the Gemora.

For those without immediate access to an Igros Moshe, here's what is written there:

יא) האם מותר לברר כפות ומזלגות ע"י שיזרקם קודם על השולחן ויפרדו

(כי הא דשבת ע"ד ע"א ושדא קמייהו וברש"י שם).

תשובה: היא עצה טובה.