The first model 19 production run (Combat Magnum through 19-8) are fairly similar in structural detail. By reputation the weak spot was the flat/thinner bottom of the barrel forcing cone; there was not an "Endurance Package" modification as done on N frames but regular unlocking with heavy loads (as in heavily loaded model 29s) was not an issue as far as I have read or seen.

The current model 19-9 has the multi-piece barrel assembly and a good quality reputation, so if you are looking for one without the potential issue of older guns both it and the current model 66 may be good choices for you.

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Alan
SWCA LM 2023, SWHF 220