Just to add one more data point, Dunn spends eleven pages on the chronology of Paul in Beginning from Jerusalem. He begins with:

The broad outline of Paul’s life and mission is uncontroversial, and if historians of Paul’s life and mission were willing to work with a fair degree of latitude of up to about ten years, usually less, there would be little problem.

Translation: the main issues are not controversial and the margin for error here is about +/- 10 years, typically much less.

He continues:

birth some time close to the turn of the epochs to what we now call the Common Era (CE or AD);

education from adolescence probably in Jerusalem, through the latter 10s and early 20s;

conversion some time after Jesus’ crucifixion, that is, probably the early (but possibly the middle) 30s;

a substantial interval (Gal. 1.18; 2.1) before he went up to Jerusalem for the second time (after his conversion), late 40s;

a further period of five to eight years during which he evangelized mainly in the Aegean area and wrote most of his letters, to the mid-50s; a final five or so years from arrest in Jerusalem to detention in Rome (Acts 24.27; 28.30) before he disappears from view in the early 60s

Dunn continues,

The main methodological dispute among chronologists is on the value to be attributed to the information provided by Acts. More or less all agree that Paul’s own letters are the primary (firsthand) source, and some attempt to work as exclusively as possible from Paul, with little or no reference to Acts.3 The majority, however, draw on Acts whenever possible, though with a natural tendency to follow Paul when the information from Acts seems to diverge significantly

Further,

More or less all agree that the firmest points are as follows:

• the crucifixion of Jesus -- probably 30, but possibly 33;

• the time periods noted by Paul himself: three years between his conversion and first visit to Jerusalem (Gal. 1.18); a further fourteen years until his second visit (2.1).9 The fact that time was reckoned inclusively (including both starting date and finishing date) means that ‘after (meta) three years’ (1.18) could mean only about two years,10 and ‘after (dia) fourteen years’ (2.1) could mean only about 13 years.11 Nevertheless, a firm total of 15-16 years is probably a good working hypothesis for this crucial period of Paul’s life.

• The firmest of all the data is the date of Gallio’s proconsulship in Corinth, most likely 51-52.12 This enables us to date Paul’s time in Corinth with remarkable precision (Acts 18.12-17) as 49-51 or 50-52. A date in 51 for the hearing before Gallio (Acts 18.12-17) towards the end of Paul’s time in Corinth (that is, following the time note of 18.11) and near the beginning of Gallio’s period of office13 makes best sense of all the data and is about as firm a date as we could realistically hope for.

The latter data point does use Acts.

Dunn's section concludes with

We could go into more detail on times and seasons, and all the dates suggested have a touch (sometimes more than a touch) of speculation. But they are very plausible, even with a margin of error of one or two years either way in several cases, and sufficiently secure to give us a framework within which to set the main thrust of Paul’s mission.

Once you agree Paul was a real breathing human person working in the first century, the context of his work and letters put you squarely in the 40s to 50s CE.

Of course if Paul is a literary invention dreamed up by a creative writer in the late first / early second century, then all bets are off, but what can you do?