My brief S&W warranty experience with similar, but different, circumstances.

My 442-1 was ~5 months old in December 2015 @ ~1500 rounds when some internal pin broke (unknown which one, whether hammer or trigger). After ~2 months, (realize this is the holiday period with personnel off and probably a factory shutdown) S&W replaced the entire firearm as, apparently, S&W doesn't have a method of replacing just one pin in these models.

S&W even reimbursed the dealer fees as, since I was in California at the time, the new gun had to back through an FFL with the forms & fees (& 10 day wait prior to bring the gun home).

Whether the OP's situation is different due to time between warranty claim and purchase or if S&W is becoming stricter with claims is unknown.

My listed 642-1 was bought in the year 2000 and has had zero problems with an unknown round count, but over 3400 rounds (I didn't always keep a round-count log on all my firearms).

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