SCHEMA:
CREATE TABLE table_name_6 (shell__lb_ VARCHAR, time_to_ft__m__at_40°__seconds_ VARCHAR)
USER:
What is the weight of the shell that reached its maximum height at 40° in 12.6 seconds?

QUERY:
SELECT shell__lb_ FROM table_name_6 WHERE time_to_ft__m__at_40°__seconds_ = 12.6