I was searching through Google for information comparing all the smallest 9mm's currently available and I didn't find a "list" like I was wanting, just mainly people talking about a few different guns here and there. So I spent many hours compiling a list of all the smallest 9mm's I could find. Here is what I came up with:
Springfield XDs 3.3- 6.3"x4.4"x0.9"; 23oz; 7+1rnd; 7# trigger; $349
Ruger LC9s Pro- 6"x4.5"x0.9"; 17.2oz; 7+1rnd; 5# trigger; $229
Sig P365- 5.8"x4.3"x1"; 17.8oz;10+1rnd; 5.5# trigger; $499
Bond BullPup9- 5.1"x4.2"x0.96"; 17.5oz; 7+1rnd; 7# trigger; $891
Diamondback DB9- 5.6"×4"x0.8"; 11oz; 6+1rnd; 5.5# trigger; $156
Kimber Micro 9- 6.1"x4.1"x1.1"; 15.6oz; 7+1rnd; 5.75# trigger; $515
Kahr CM9- 5.42"x4"x0.9"; 14oz; 6+1rnd; 6.5# trigger; $285
S&W Shield- 6.1"x4.5"x1"; 18.3oz; 7+1 rnd; 5.5# trigger; $339
Sig P938 BRG- 5.9"x3.9"x1.1"; 16oz;7+1 rnd; 7.5# trigger; $510
Glock 43- 6.26"x4.25"x1.06"; 16.2oz; 6+1 rnd; 5.4# trigger; $419
Kel-Tec P-11- 5.6"x4.3"x1"; 14oz; 12+1 rnd; 9# trigger; $204
Kel-Tec PF-9- 5.85"x4.3"x0.88"; 12.7oz; 7+1 rnd; 5# trigger; $161
Now I want to add a few "notes" to the above list. I wanted to keep the representation of these weapons as "small" as possible, so the dimensions of each is with their flush mount mags. This means the round count is also a reflection of the flush mount mags. Some of these pistols do have options with a mag that extends from the bottom of the handle increasing the size and the round count by 1 or 2 rounds.
The prices are the cheapest prices I currently found for each weapon as of 1/2/2019. This does not include possible shipping fees (a lot of them were free shipping) and FFL transfer fees.
Now that the list is made. I started doing HOURS of research on each of these firearms. For my own personal preference, I wanted not only a small, lightweight 9mm, but also a reliable one. Now reliability is a relative term that almost comes down to opinion to a degree. Some people make find that 4 or 5 failures to feed or eject in 100 round is acceptable. Some may find it acceptable in 1,000 rounds. I personally do not trust a firearm to my life unless it is 100% reliable. Now that you know how I feel about it, lets move on.
So my sources of information came from videos such as Hickok45, NutnFancy, Military Arms Channel, and Colion Noir. I also read multiple articles from all the "big name" gun magazines on each of these pistols as well. I literally spent HOURS on each pistol.
One that was disappointing to me, was the Sig P365. From specifications alone, I really wanted this gun to be a possible future carry gun for me. After watching multiple videos where the gun literally broke on camera, and a ton of complaints of broken firing pins (strikers) and trigger springs, I could no longer keep it on my list of "reliable" weapons. Sig even openly admitted they had some parts that the carbon content was out of specs, but they did not specifically say when it was fixed and what all it related to. Hopefully in a year or so, they will work on the bugs out because this pistol has potential.
What is also interesting looking at the list, is a lot of people felt the Sig P365 was revolutionary to creating a small, lightweight pistol with a 10 round capacity. After I made the list I quickly realized that Sig was in fact not the first to do this. In 1995, Kel-Tec released the P-11 which is a hair shorter in length, weighs less and carries 2 more rounds that the Sig P365, all for less than half the price. Just a interesting note.
So back to reliability, here is what I came up with after all the research:
Glock 43
S&W Shield
Ruger LC9s Pro
Kel-Tec PF-9
Kel-Tec P-11
Springfield XDs 3.3
Sig P938
Kimber Micro 9
Those are the reliable "small" 9mm's. Now I know what some are going to think. How did Kel-Tec end up on this list? Trust me, I was shocked to find that after 200 to 300 rounds (many times less) these pistols were 100% reliable. Yes they are kind of ugly and rough around the edges, but every review I watched with them where they had been broken in, they were 100% reliable. Specifically, NutnFancy liked the Kel-Tec PF-9 so much that he made it his daily carry gun for a number of years. He trained with it almost on a weekly basis and fired thousands of rounds through it with no issues. He is typically very critical of pistols so I was really surprised to see him choose it as his daily carry gun.
Now I feel like some will also wonder why the Kahr did not make the list. This was the pistol that was the hardest to decide if I should call it reliable or not. Its not that they are technically "unreliable", but rather owners and reviewers report they are picky about ammo types. Even after 200 or 300 or even 500 rounds of break in, there are tons of reports of them not cycling a fairly wide variety of rounds. Yes if you take the time to find rounds it likes, I have read they are reliable. The other thing that concerned me about Kahr is that almost every customer who had a issue with their weapon and then contacted Kahr was met with bad customer service. Many people complained that Kahr would blame the issues on the customer and just basically be rude about the whole situation. Some of these owners seemed to be competent and experienced gun owners. There just seemed to be a pattern of Kahr providing bad customer service.
So I wanted to shrink the list even more at this point, and here is my though process. When searching for the smallest 9mm's, I also want something that is lightweight as well. Well the Springfield XDs 3.3 weighs almost as much as a Glock 26. So if I was willing to carry that kind of weight, I would simply carry a larger capacity as well such as the Glock 26, so the Springfield XDs 3.3 was off the list due to its heavy weight.
Next I chopped the Kel-Tec P-11 of the list because personally, I don't like the idea of a 9 lb trigger pull. Yes I found detailed instructions that can be done by yourself or a gun smith to lighten the trigger up to about 7 lbs which is a lot better, but still not quite where I would like it, and personally I don't want to mess with it.
I also removed the Sig P938 because again, I felt the 7.5 lb trigger is a little heavy for me. I am sure there are way to lighten it up, but I really don't want to mess with it. It is also on the higher end of prices out of these weapons. Other than those personal prefrences, it is a reliable weapon.
I removed the Kimber Micro 9 as well, because I am not a fan of a weapon with a safety. I think it is something a lot of people would forget to turn off in the heat of the moment when being attacked. Yes this can be overcome with a lot of training, but for the average person, I would not recommend this. If you are willing to put in the training, this is a reliable great weapon.
So if someone was going to ask me now, "hey, I am looking for a lightweight, reliable, small 9mm, what do you recommend?" My answer would be for them to look at these:
S&W Shield- 6.1"x4.5"x1"; 18.3oz; 7+1 rnd; 5.5# trigger; $339
Ruger LC9s Pro- 6"x4.5"x0.9"; 17.2oz; 7+1rnd; 5# trigger; $229
Glock 43- 6.26"x4.25"x1.06"; 16.2oz; 6+1 rnd; 5.4# trigger; $419
Kel-Tec PF-9- 5.85"x4.3"x0.88"; 12.7oz; 7+1 rnd; 5# trigger; $161
Clearly the Kel-Tec PF-9 wins the "bang for the buck" award here, and the "lightweight" award as well. I am really happy to see there is a manufacturer producing a quality firearm at this price for people who are on a budget. I personally have owned a lot of Glocks, and I am very comfortable with them, so I feel like I would likely choose a Glock 43. The Ruger LC9s by far received the highest praise for its trigger out of any of these guns. Every reviewer was amazed how nice the trigger was, just something else to keep in mind. Honestly I wish I could purchase all four of these and spend about 1,000 rounds with each and then choose. Regardless of which of those four you choose, I don't think you will be disappointed. I hope the research I did here helps someone else who maybe doesn't have the time to research this much.