Sports Shooting United States | High pressure charges in Shell Shock NAS3 enclosures


by Brad Miller, Ph.D. –
Friday, September 28, 2018

WARNING: All technical data in this publication, especially for manual loading, reflects the limited experience of people using specific tools, products, equipment and components under specific conditions and circumstances which are not necessarily reported in the article and over which the National Rifle Association (NRA) has no control. . The data has not been otherwise tested or verified by the NRA. The NRA, its agents, officers and employees accept no responsibility for the results obtained by the persons using this data and accept no responsibility for any injuries or consequential damages.

Shell Shock Technologies’ new 9mm Luger case designed in two parts is appearing in more and more factory ammunition. This innovative design has a stainless nickel alloy cylinder body attached to an aircraft grade nickel plated aluminum base.

Figure 1. The new enclosures from Shell Shock Technologies are made from two separate components, one nickel alloy and the other aluminum.

The nickel alloy shell (NAS3) housings allegedly have advantages over conventional brass housings. They’re 50% lighter, less abrasive, self-lubricating, corrosion resistant and won’t split, chip or crack, and they’re magnetic so you can pick them up with a magnet.

Reloading the NAS3 is no different from loading brass crates except for the requirement of a special sizing die and flaring die made by S3 Reload. Housings require lubrication for the sizing step, even though the special sizing die has a carbide insert. The calibration die can also be used with ordinary brass housings.

Shell Shock claims they are stronger than conventional brass housings and have a pressure rating of 65,000 psi. This caught my eye, and one of the things I wondered about was if they could be used for very high pressure loads like 9 Major.

We often think that the powder chamber holds most of the maximum pressure, but the pressure also pushes the primer back through the flashhole. If the pressure is too high, the priming metal will show signs of tension as it flattens and flows, and the priming hole may be stretched, making it too loose to be reused.

I was wondering how the primer pocket in the NAS3 the aluminum head of the housing would withstand very high pressure. Brass housings, when loaded at very high pressure, can, with just a few uses, end up with loose pockets of primer. Shooters loading 9 Major for competition, where pressures can easily exceed pressures of 9mm + P, may end up with loose bait pockets after just a few loads.

The durability of the NAS3 The primer pockets of the holsters were tested by pulling high pressure charges into new casings and then re-priming them to assess how “loose” the primer pockets were.

The first high pressure charge was a + P charge published in the Western Powders manual. This was a 115 grain jacketed bullet seated at 1.1 inch by 6.2 grain True Blue fueled with CCI 500 primers. The Western manual states that this charge produced 38,373 psi and 1197 fps in their. 4 inch test barrel. This charge was clocked at 1277 fps from my 4.6 inch Lone Wolf cannon and 1295 fps from my 5 inch Kart cannon.

The + P charge has been triggered four times in the same NAS3 case. The primer bags were in good condition. They weren’t as tight as the new cases, but they weren’t loose.

A second high pressure test was carried out by loading boxes at 9 major performance levels. Nine Major (or Major 9) is a term used by competitive shooters who load 9mm Luger ammunition to achieve a specified power level required in USPSA / IPSC competitive shooting sports for Open Division pistols (typically having a compensator and an optical sight). The power factor is defined as the weight of the bullet multiplied by the speed divided by 1000. In USPSA, the major power factor is 165, which means that a 115 grain bullet must achieve at least 1435 fps to be successful. to qualify. Most shooters load their ammunition at a power factor of around 170-172 to ensure it meets requirements. These speeds and pressures generally far exceed the current performance of 9mm Lugers and should only be loaded by very experienced reloaders and only used with guns specially designed for this type of ammunition. The 9 Major chamber pressures can be extremely high with certain loads and may exceed the SAAMI pressure limits of 38,500 psi for 9mm + P.

A test was carried out to check the speed of the loads in the NAS3 compared to conventional Starline 9mm brass housings. Both cases were loaded with Federal Small Rifle Primers (205), 7.8 grains of AutoComp, and a 115 grain Winchester JHP bullet sitting for a total length of 1.150 inches. They were fired from a Glock 19 with a 4.6 inch Lone Wolf cannon. The Starline brass load averaged 1521 fps, and the NAS load3 case was faster with an average of 1577 fps. Oddly enough, the NAS3 enclosures have slightly more internal capacity than Starline enclosures, so one could predict that the NAS3 case would produce a little less speed. However, this was not the result, and I compared these same two cases with standard pressure loads and the NAS3 the cases reliably produced higher speeds with the same load.

The speed of the Shell Shock was recorded with a Shooting Chrony chronograph at approximately 10 feet.

Table 1. Speed ​​was recorded with a Shooting Chrony chronograph at approximately 10 feet.

A charge was developed in Shell Shock cases using Winchester AutoComp 7 grain and a 115 grain FMJ Zero bullet placed at 1.150 inch OAL. This load produced 1475 fps (169 power factor) in the 4.6 inch Lone Wolf cannon and 1521 fps (175 power factor) in the 5 inch Kart cannon. Thirty-seven percent of those pods had primer pockets too loose to safely hold a new bait after a single bake. The primer pockets in the remaining cases were noticeably looser than the new cases, but were still tight enough to be reused, although I would hesitate to use them for that same high pressure load.

Two 9 major charges: one with a Zero FMJ bullet and the other with a Hornady HAP bullet.

Figure 2. Two 9 major charges: one with a Zero FMJ bullet and the other with a Hornady HAP bullet.

AutoComp is one of the fastest burning powders used for 9 Major. A second set of 9 Major ammunition was loaded with Accurate # 7, a slower burning powder. This powder should, in theory, be able to achieve the same power factor level as the AutoComp but at a lower pressure.

Four different charge weights (9.0, 9.3, 9.6 and 9.9 grains) of Accurate # 7 were loaded in 10 new cases each with Hornady HAP 115 grain 1.150 inch OAL bullets. The cartridges chronographed from the 5-inch Kart cannon at a power factor of 170, 176, 179, and 183, respectively (1477, 1533, 1553, and 1594 fps, respectively). None of the 170 power factor boxes had loose primer pockets, although many were not as waterproof as the newer boxes. One of the 176 power factor boxes had a primer pocket that was too loose to trust future loads, but the other boxes were fine. None of the 179 power factor boxes had loose primer pockets. With the 183 power factor packs, a primer pouch was a bit loose but would likely take a standard pressure load. A primer was so loose that it fell off during handling! The primer pockets in the remaining eight cases were not as tight as the new cases, but were still reasonably tight.

The speeds and power factors for the AutoComp load show the first speed and first power factor of the 4.6 inch Lone Wolf cannon and the second speed and power factor of the 5 inch Kart cannon.  * A worn primer has fallen out of the housing during handling.

Table 2. Speed ​​was recorded with a Shooting Chrony chronograph at approximately 10 feet. The speeds and power factors for the AutoComp load show the first speed and power factor of the 4.6 inch Lone Wolf cannon and the second speed and power factor of the 5 inch Kart cannon. * A worn primer has fallen out of the housing during handling.

These extreme pressure tests show that NAS3 The housings can be used for high pressure and 9 major loads, but depending on the powder and the level of performance required, the primer pockets may come off after one or more loads, just like the brass housings.

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