Ticket ressies necessary in Oct?

The British Museum, British Library and Victoria & Albert Museum are free unless there's a special exhibition you want to see. The latter require tickets, usually timed, and those on popular subjects can sell out by early in the day if not before.

The British Museum was crowded all four times I visited it earlier this month. I gather it's worst on weekends, Fridays and rainy days. I arrived shortly after it opened on a Friday morning and stood in line for about 30 minutes because the secunity equipment at the rear entrance had broken and we all had to walk around to the front of the museum, where the line is usually a bit longer. I think the line is typically shorter later in the day, but people often spend a long time n the museum, so it feels as if it gets more crowded as the day goes on. Perhaps it would work well to show up 15 minutes before opening, but I've never tried that.