Please be patient with me as this is my first time posting anything to any kind of website. I apologize ahead of time if i'm doing this wrong. My question is I currently have one of my 645's at the gunsmith getting a complete polish job. Before everyone jumps on me for ruining the beautiful finish of such a wonderful gun, I also have two original 645's tucked away safely in my gun case. This is my one to "play" with if you will. The gun is currently in the final stages of having every visible part polished to a mirror finish. Except the back grip insert. I may be wrong but I believe it is made out of some sort of cast alloy. I have 4 or 5 spare inserts but before i ruin them all i'm looking for some input. What is the best method to get the insert to match the rest of the gun? The smith doesn't seem to think it can be chrome plated and he's already tried to polish it with no luck. But then again I see different websites of different chrome plater's and anodizers and they advertise being able to do what I need done. What would you do in my situation? I have a good friend with a complete CNC and cad set up he uses to make 1911 grips but its gonna cost me a lot to get to get a program set up just to make that one little piece out of something more polish friendly. From a fellow S&W enthusiast to another, thanks in advance for any helpful info you guys can share.

I always assumed it was made of some type of cast stainless steel. How much does it weigh? If light maybe it is aluminum, heavier maybe it is stainless steel. Curious that it can't be polished either way though.

I wonder about the competence of a "gunsmith" who does not recognize plastic! The back strap on a Model 645 is gray plastic. It will never polish.

(For what it is worth, there might be professional help available for an obsession to have everything shiny.)

The back strap on my 559 is aluminum and on my 659 it is stainless steel. Why would the 645 be any different?

It is cast aluminum. The checkering will deform upon impact, much easier than stainless steel.
P.S. where did you manage to find all of those spare parts? That particular part has not been available for some time.

Quoting one's self is probably some sort of intellectual incest, but NEVER MIND! When the original poster reported that the backstrap would not polish, I wondered why not, since I thought the backstrap on a Model 645 was aluminum. I made a quick trip to the vault room, pulled out a very early Model 645, tapped on the backstrap with my fingernail, looked at the "texture," concluded that the back strap was gray plastic and came back up and posted my erroneous conclusion. Just goes to show you that a Colt guy should not be commenting on Smith & Wesson issues! I apologize for my careless mistake.

The backstrap IS aluminum. With that conclusion, I wonder why the gunsmith cannot polish it? It should polish easier than the stainless steel. Of course, how one would polish the checkering is a challenge, but the uncheckered portions should polish easily, even if the resulting "color" would not match the polished stainless steel of the rest of the gun.

Again, I apologize for my careless mistake.