Coming in from left field here, when I had my custom stainless built (Project 616) the only barrel I could find to have rebored was a 4" (Model 617) and I was a little bummed. Now that I have had it done, I don't think I would want to change it, even if I could. Remember that the vast majority of the service revolvers carried by uniformed LEOs for decades were 4" M&Ps and Model 10s. Mine carries quite well in a an old break front Bianchi service holster.

I guess the K-32 with 4" barrel was regarded as too short for targets and too puny for self defense; so being "neither fish nor fowl" it was allowed to die. More's the pity.

BTW, I'm beginning to really lust after these 4" K-32s being shown in this thread. You can't beat class!

Froggie