This thread got me very curious as to the throats on several of my revolvers. I managed to acquire the use of several pin gauges and did some measuring this evening. My .38 Spl S&W M-36 all throats measured .357". My .38 Spl Taurus all throats measured .357". My .357 Mag S&W M-19 all throats measured .357. However, my .38 Spl Charter Arms Undercover all throats measured greater than .359" (the largest pin gauge that I had). I suspect they would have measured at .360".

So....based on my findings and the information from others on this thread, I suggest that you take it to a competent gunsmith that is knowledgeable and experienced with chamber reaming and and get that addressed. If a .356 gauge will not fit, something is wrong. You might want to give S&W a phone call. They may cover this under warranty.

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