Remarks in some other post about the ascent angle on Challenger and it got me
thinking about the multiple factors that worked together.

1) The used SRB casing was way out of round. Don't recall if it was even in
spec. The poor assembly guys had to put a winch on it to force it into round so
that they could join it to the next section. The O-rings would have failed to
seal regardless of temperature (maybe.)

2) Launch temp far outside of experience. Cold hardened rubber O-rings
wouldn't seal/slow response.

3) Highest winds aloft.....put torque on SRB seals.

4) Highest launch payload. Overall higher stress on structures?