[His]

Which compact or full-size pistols have slimmest, smallest grips?

[Calhoun]

Kahrs are pretty slim. So are 1911s.

Anything else you can tell us about what you are looking for? Caliber, frame material (steel, alloy, polymer), intended uses (range, home defense, CCW)?

[His]

I would like to see more pistols on the market with grips the size of the new Walther PPS 9mm. Perhaps there are some I don't know about.

[CWL]

You are aware that most non-polymer pistols will allow you to replace the stock grips with thinner ones? Nowadays, there are even polymer guns with multiple grip options.