Not really.

If both of the guns are older models that have a hammer mounted hammer nose (firing pin) you could try swapping the hammers in the guns. If the hammers are compatible, and the hammer from the more "reliable" model restores reliability 100% of the time, then you've pretty much narrowed the problem down to the hammer.

Other than a defective hammer nose there are a couple of other possibilities, including something called "hammer hits rebound". Not a likely cause, but possible. Also, just to double check, put empty casings in the gun and check the rear gauge again...make sure the casings are fully seated in the chambers before a measurement is taken.
Any idea if the misfires are occurring in the same chamber each time?

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Ret. LE, FA Instr, S&W Armorer