What is the difference between 9mm bullets

When loading a single column magazine, a gap also will eventually appear between the front of the top round and the one under it. This is called the nosedive gap. As more rounds are added, the nosedive gap gets bigger.

The nosedive gap appears with straight-walled cartridges, but the 9mm's taper can increase the gap by about one degree more than a straight-walled cartridge for every round added to the magazine see slideshow.

The taper on one side of a 9mm Luger cartridge is about one-half a degree. A larger gap means greater potential nosedive. Attempts to change some aspect of the magazine or the follower produce limited results. But all these efforts have overlooked the obvious: All that is required for an immediate improvement in feeding reliability is to get rid of the taper, and here is the data to prove it.

I conducted extensive tests with a prototype cartridge that demonstrate clear benefits of creating a new 9mm cartridge with straight walls. The benefits are impressive.

A straight-walled case dramatically improves cartridge feed angle and feeding reliability. A prototype straight-walled cartridge was made from. The case wall and rim diameter of the. The prototype cartridge was made by trimming the Lapua cases to 9mm Luger length of up to 0.

When loaded, the prototype cartridge will be referred to as the 9mm Automatic 9mm Auto. In concert with creating this prototype cartridge, functional tests were conducted to assess to what degree cartridge dimensions affect feed angle and feeding reliability.

These tests examined cartridge taper and rim width. I prepared special ammunition for these tests in order to maintain a similar overall length profile. The test ammunition, except for one factory load, was handloaded with Remington grain FMJ round nose bullets to 1. Five different tapers were tested: no taper 9mm Automatic ,.

Brand new Remington 9mm Luger brass averaged 0. These cases were not sized prior to loading in order to maintain their original shape of straight, non-parallel sides sized 9mm Luger brass often results in "hour-glass" shaped loaded cartridges.

The profile of the Federal round was very similar to the handloaded cartridges, and was used as an example of factory ammunition.

When sized with a. A second group of fired 9mm Automatic cases was partially sized until they had a 0. Cartridge feed angle was measured from high-speed frames per second video. Feed angle is defined as the lowest angle the cartridge achieves prior to hitting the feed ramp.

The camera recorded cartridge behavior as it was stripped from the magazine. The test gun was a custom-built Caspian single column pistol with a ramped 9mm Luger barrel. A single McCormick. This condition permits maximum nosedive, which allows for an evaluation of the effect of different cartridge dimensions on feed angle.

Also, some shooters including the author use. A total of rounds were video recorded and analyzed for feed angle. Feed angle for all cartridge designs is lower when more rounds are in the magazine. This occurs because the nosedive gap gets bigger as more rounds are loaded in the magazine regardless of taper.

However, the nosedive gap is greater with tapered cartridges, and more taper means an even larger gap. The larger the nosedive gap, the greater the nosedive and the lower the feed angle. In the figure below, the feed angle of the 9mm Automatic black line is at the top of the other lines at nearly every point, indicating a consistently high feed angle.

The plotted values are the cartridge angle relative to the magazine feed lips. The angle of the tapered cartridges was adjusted in order to show the angle of the measured cartridge's central axis on this and subsequent figures. The important feature in the figure is the large difference in feed angle between most of the tapered cartridges and the straight-walled 9mm Automatic when there are four rounds and more in the magazine.

The difference in angle can be quite large, up to over seven degrees round 5 with the most tapered brass 0. The 0. Even a taper as small as 0. The least amount of taper 0. Note the slight improvement in feed angle for some of the more tapered 9mm Luger cartridges with rounds in the magazine.

This is an artifact of it being a 10 round capacity magazine, as this improvement was not evident in a 15 round single column magazine that was tested.

Presumably, when the magazine spring is near full compression, the pressure can affect the feed angle of tapered cartridges. Several straight-walled. Thirty-eight Super Comp Starline and. However, they have slight rims that measure about 0. By comparison, the. The 9mm Steyr is another straight-walled case, and Barnes indicates a rim 0.

Actual rim width varies somewhat in all examples. Rim width matters because the rim can enhance nosedive. The rim of the upper round is normally positioned in the extractor groove of the underlying round when they are in the magazine. During feeding, the slide pushes on the upper rim base of the cartridge. As the round is pushed forward, a rim wider than the case wall will drag on the underlying cartridge once it moves past the extractor groove. The push on the upper part of the rim and drag on the lower part of the rim combined with a nosedive gap encourages the cartridge to nosedive.

I tested several of these case designs trimmed to 9mm Luger length to assess the effect of rim width on feed angle. I selected cases with a rim of. Rim diameter measurements indicate rim diameter minus head diameter. Cases with rims less than. Cases were loaded with the Remington grain bullet as described above.

For this reason, the two are not interchangeable. At 23 millimeters in length, this cartridge is not interchangeable with the 9mm Luger. This round has different dimensions all around, including bullet diameter and neck diameter compared to the 9mm Luger. It should load perfectly in any weapon designed for the cartridge. However, because 9mm NATO is a military round, manufacturers load it to higher pressures. This delivers greater velocity and energy. You may want to make sure your 9mm handgun is rated for higher pressures before you purchase and use 9mm NATO rounds.

If you are not an expert, the firearms industry can seem a little intimidating. However, understanding the various definitions for ammo choices will help you communicate with other firearms enthusiasts and will be useful when you are looking to purchase.

There are a lot of terms, but knowing which terms apply to which cartridges will make you a more confident and informed gun owner, and will also enhance your enjoyment of all shooting sports! Let your fellow shooters know — share this article using the Facebook, Twitter and other social media icons below. The more we all know, the better organized and stronger the shooting and hunting community will be. The Lodge AmmoToGo. Look for tips for the range here. Login Register. Home Blog 9mm Ammunition: History, Specifications and types of 9mm ammo.

Specifications Of 9mm Ammo With different bullet design, 9mm bullet have different weight, casing, and pressure. Unjacketed: Unjacketed ammo features plan lead bullets with no outer casing, making them slow and less powerful. Full metal jackets FMJ : 9mm FMJ ammo is the most common and features a lead bullet encased in copper or another hard metal. They are used primarily for target and range shooting. These bullets expand on impact, increasing stopping power, and are used by the military, law enforcement, and for self defense.

Open tip match OTM : OTM ammunition is designed for target and competition shooting, similar to hollow points, but not as deadly, these cartridges are accurate and consistent. Ballistic tips: 9mm ballistic cartridges are designed for pistol hunting, bringing stopping power and distance.