Is The Glaser Safety Slug Good for Self Defense?

posted on October 7, 2020

Glaser Safety Slugs come with either a blue or silver tip and are available for 13 different defensive-handgun cartridges.

After the 1986 Miami shootout where two FBI agents were killed and five were wounded, the standard/FBI-approved, defensive-handgun bullet would become a jacketed hollow point that expanded to about 1.5 times its original diameter and penetrated to at least 12 inches in 10-percent ordnance gelatin. Thirty-four years later, that’s still the projectile most trusted by law enforcement and those carrying handguns for self-defense. This type of ammunition essentially balances expansion and penetration in an effort to provide a hypothetical optimum degree of “stopping power,” whatever that is, against bad guys.

Alternative defensive projectiles offering deeper penetration or wider expansion and even fragmentation have come and gone since 1986. One unique load that could be classified as a specialty round has remained, and in fact has been available since the mid-1970s. And, although it’s undergone a variety of modifications and renditions, it can still be had. It’s called the Glaser Safety Slug.

According to the Cor-Bon website, the Glaser Safety Slug “was designed in response to the possibility of having to use a handgun on an airplane by the Sky Marshals. The concerns at the time were over-penetration on soft tissue and ricochets on hard surfaces and possible excess penetration.” According to online sources, the Glaser was designed by Jack Canon, with the original loads produced under the banner of Deadeye Associates. In 2002 Cor-Bon purchased the company and has been manufacturing the ammunition ever since.

The Glaser Safety Slug, in its current form, is a bullet with a thin-copper jacket capped with a spherical, polymer tip that provides a bullet profile very similar to an FMJ (full-metal-jacket) projectile. Behind this polymer cap is the hollow core of the bullet, which is filled with either No. 6 lead shot (Safety Slug Silver) or No. 12 lead shot (Safety Slug Blue). When the Glaser Safety Slug—Blue or Silver—impacts soft tissue, the bullet ruptures immediately, releasing the lead shot. The jacket fragments will penetrate to between 1 to 4 inches, and the No. 12 shot will push as deep as 6 inches, with the No. 6 shot going as deep as 8, depending on the cartridge. The shot also radiates outward in a cone that can be as wide as 4 to 5 inches.

As you might expect, the fragmenting bullet jacket and shot destroys a lot of tissue. This is partly because lots of tiny projectiles are being pushed through flesh, and partly because of the extreme velocity at which they are traveling. The velocity is high because the projectiles are so light. A .45 ACP Glaser Safety Slug weighs only 145 grains and, out of a 5-inch barrel, will have a muzzle velocity as fast as 1,350 fps. The 9 mm and .38 Super Glaser Safety Slugs weigh only 80 grains and have respective muzzle velocities of 1,500 and 1,650 fps.

There are some advantages to this type of bullet performance. Unless you’re shooting a cartoonishly tiny bad guy, the chances of over-penetration are virtually non-existent. Additionally, due to the fragile makeup of the bullet, ricochets are rare—the bullets tend to break apart on hard surfaces—and with minimal projectile weight the shot and jacket fragments do not travel very far. If they do, they do so with minimal energy or potential for lethal wounding anywhere except perhaps some extremely unlucky location. For these reasons, some consider Glaser Safety Slugs a good choice for use where there is a high population density, such as in markets, hospitals and courtrooms.

Do Glaser Safety Slugs work? I’ve tested 50 rounds or so of the ammunition in 9 mm and .45 ACP out of several pistols with no stoppages. I have, however, heard reports of questionable reliability. This does not surprise me; some semi-automatics are not tuned for high-velocity, low-mass projectiles. I’ve also tested both the Blue and Silver loads for both chamberings in 10-percent ordnance gelatin. In my tests, it performed as described and advertised every time. But again, reputable folks have recounted instances where the bullets failed to open in gelatin.

Another concern when using Safety Slugs centers around intermediate soft targets. Many people hold up a hand or arm defensively before getting shot. If the Glaser fragments on these intermediate targets, there is nothing left to impact vitals. Also, both bodybuilders and the morbidly obese may have more that 6 to 8 inches of soft tissue over their vitals, which could prove problematic for these projectiles.

Unlike some of the more modern unusual munitions marketed for self-defense, Glaser Safety Slugs were part of the thought-to-be-mythical, privately funded, 1991 research project known as the Strasbourg Tests. During this study, 611 goats were allegedly shot with a wide range of cartridges and munitions, and the Glaser was one of the top performers, at least with regard to incapacitation time. Unfortunately, humans rarely need to defend themselves from attacking goats, and how this all relates to stopping bad guys is debatable.

However, thanks to its one-time popularity with law enforcement, with the Glaser Safety Slug we have actual street results to reference. A controversial study by Marshall and Sanow cites more than a dozen real-world shootings with Glasers. While some folks—including me—question their “stopping power” conclusions, their data with regard to actual shootings should not be summarily dismissed. Out of the 15 shootings described, the results are mixed, and mostly dependent on the Glasers’ ability to enter the chest cavity and act as it is designed to do. When that happens, this ammunition seems to stop attacks quickly if not instantly.

Cor-Bon still offers both versions—Blue and Silver—of the Glaser Safety Slug. They are available in .32 ACP, .380 ACP, 9 mm, .38 Super, .38 Spl., .357 SIG, .357 Mag., .40 S&W, 10 mm, .44 Spl., .44 Mag., .45 ACP and .45 Colt. Not all that long ago, Glaser rounds were sold in blister packs of six, but today it’s packaged in 20-round boxes and retails for between $20 and $40 per box depending on the cartridge.

I would not consider the Glaser Safety Slug to be the best defensive handgun round out there, and it is surely not an all-around, defensive-handgun load. At the same time, there is a record of successful stops using this ammunition, and the expansion and fragmentation the company claims is supported in testing.


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