Few things are as disconcerting as discovering that your new semi-automatic has a jam, misfeed, or stove-pipe 2 out of every 10 shots. AARRGGHH!!
However, don’t despair yet. If it is a very inexpensive gun, well, you get what you pay for. Bargain guns may have loose tolerances, short-cuts in the casting or milling processes, or other issues that cause this, but read on. In many cases the rest of this article can resolve those problems.
While some manufacturers seem to not have this problem, others do, at any price point, and will usually warn you about the need to break in the gun. Kahr is a well-respected gun maker, but the owner’s manual clearly states that the gun cannot be considered reliable until you have shot 400 rounds through it. The issue is metal-against-metal friction, such as the rails and grooves on the slide and frame. Even when the metal looks smooth and machined, at a microscopic level, it is not. Those surfaces have to be worked down (polished) slightly, preferably by the matching piece of metal against which it runs. That process is called lapping, and is common in many industrial applications. Breaking in a pistol, then, is simply running the reciprocating action (the slide) enough times to polish those mating surfaces. Most people do that by firing the gun. A cheaper way is to rack the slide 200-300 times. That can be made easier by removing the recoil spring. It will be more effective if you don’t lubricate the slide.
By the way, this is not a problem for revolvers, as they do not have any rapidly reciprocating mechanisms.
I have had several semi-autos, made by CZ, Smith & Wesson, Walther, and Dan Wesson, that worked flawlessly right out of the box, but some perfectly fine guns have needed that break-in period. I bought a Ruger recently that would not fire 3 shots in a row without a malfunction, until I got to about 300 rounds. After that, it worked fine. It still will not consistently feed and extract Federal brand ammo, but 5 other brands work fine. That is not a break-in issue, but ammo sensitivity.
The reasons are complicated, and not easily understood, but some guns will not consistently handle certain brands of ammo. The design and angle of the feed ramp, the slope and contour of the bullet nose, and sometimes issues related to the width and shape of the cartridge rim can all contribute to this. The short answer is, if your gun won’t work right with a certain brand of ammo, don’t buy that brand.
If no brand of ammo will work at least 99% of the time with a gun, contact the manufacturer. Most of them will make every effort to make it right, often at no charge.
When I was a kid, automobile manufacturers used to tell buyers to keep their new car under 50 mph for 500 miles, to break in the engine. Now, they are essentially broken in at the factory. Some semi-autos will need a break-in period, but some will not. If yours is acting up, clean it well and lubricate it, and put mileage on it. That will usually solve the problem.