Follow up to my earlier question below. I used the 'Contact Us' link and what follows is the queries and replies.

Q: K-frame revolver general question: When/what serial number were the K-frames first rated for .38 Special +P ammunition? Thank you for your time.

A: A serial number range unfortunately won't answer your question. Whether or not a revolver can handle +P depends on it's revision number. The revision number used to indicate the ability to use +P is different for each Model revolver. If there is a specific revolver Model in question, we can provide you the dash number you will need to look for.

Q: My query was more of a general nature rather than against a specific model. I can appreciate how there isn't a 'line in the sand', so to speak.

However, from your explanation, can I safely assume that ALL models built prior to your model numbering system (so called '5-screw' revolvers) will NOT be rated for +P? And then further, that some of the early model numbered revolvers also were not for +P but that would have to be on a case-by-case basis.

A: Yes, that is correct, you can safely assume that. By 1997, most of our .38 Spl revolvers were rated for +P ammunition. An example is the Model 14 which is a K frame .38 S&W spl, also known as the K-38 Target Masterpiece. This model wasn't rated for +P ammunition until 1997 in the -7 revision. The -7 revision is when we introduced the new frame process on this model, which allowed the use of +P ammunition. On this model, this revision aslo indicated the change to MIM parts. If you have a revolver in question, and it doesn't have an integral frame lug or a MIM hammer, then you shouldn't use +P ammunition, unless the revolver in question is chambered in .357 mag.

Kudos to Ashley from S&W for her answers and patience.