Side Holster Fits

I currently have a Walther P22. I love the gun's comfort and very small size which makes it very easy to conceal and very comfortable to shoot. This gun fits without a holster comfortably in my waste line on my side. I read several reviews and found that most people either love it or hate it. I'm kind of in between. It does like to jam if you do not keep the gun oiled frequently. I'm looking for something with a higher caliber with good reliability and around the same size as the P22. I do not particularly like Glock because I hate not having a hammer. So if anyone has any suggestions on a similar higher caliber but yet very small pistol with a hammer please let me know. I just need the same or similar dimensions and also light weight. Thanks.