Hello everyone, this is my first post!

I'm looking to do a quick turn around arriving from LHR at 8:10 departing back to LHR at 09:55 but ba.com will not sell me the ticket claiming I need a minimum of 120 mnutes between the flights.
This seems like an awfully long time does it not? is there anyway around it?

Also, although I am very familiar with the DUB airport after commuting there weekly for about a year, I have never done a turn around or connection there, so wondering how easy it is?

Many thanks in advance for any advice.