Shot Show Daily Report – 25 January 2024
Amend2 and retained energy downrange
Yesterday afternoon, I had the opportunity to meet Justin Klumker from Amend2 magazines (https://amend2mags.com/. Amend 2 is a great supporter of the Sawmill Showdown. I really enjoyed meeting Justin and learning more about Amend 2.
I spent today (Thursday) at the Shot Show talking to ammunition manufacturers, barrel manufacturers, and bullet manufacturers about hybrid cartridge cases. A hybrid cartridge case is a cartridge case that is made from more than one metal. Most cases today are one metal. Cartridge cases today are mostly made of a brass alloy or a steel alloy.
Sig, Norma, and a few other manufacturers are working on hybrid cases that are reinforced with steel at the base so that chamber pressure can safely increase. Safely increasing chamber pressure means the firearm can launch projectiles (bullets) that carry more energy downrange.
Sig’s .277 Fury cartridge uses a hybrid case. Norma was featuring a 7.62x51 NATO (.308 Winchester) hybrid case in their booth (see the pictures below). I talked to several barrel manufacturers about barrels that will handle the higher chamber pressures. One manufacturer has produced test (or proof) barrels that will handle more than 100,000 PSI chamber pressure.
Sig’s cartridge produces about 80,000 PSI chamber pressure compared to about 62,000 psi for 5.56 NATO. 7.62x51 NATO produces about 60,000 PSI. A .223 Remington cartridge should produce about 55,000 PSI chamber pressure. Magnum cartridges are often in the 60,000 to 65,000 PSI range. I asked the Norma rep what pressures their hybrid cartridge could handle and he said, “good question.” As soon as I find an answer to that, I will let you know but I suspect that it is likely going to be somewhere around the .277 Fury pressures.
Why go to all this trouble to have higher safe chamber pressures, especially in smaller and lighter rifles?
Projectile weapons (rifles, pistols, shotguns, arrows, spears, slingshots, and rocks … that is not all of them but you get the point) depend on retaining energy until they hit the target. Retained energy is a critical dependency for in-flight performance and for performance at or on the target. In-flight performance is the study of external ballistics and performance on or at the target is the study of terminal ballistics.
Retained energy is a key dependency for firearm projectiles (bullets). As the bullet loses energy, it loses stability. As stability lessens, accuracy decreases. Eventually the bullet slows enough to go subsonic. That transition often causes the bullet to tumble and accuracy is severely degraded.
Retained energy is also a key dependency for terminal ballistics. What happens when the projectile (bullet) hits the target depends broadly on three variables. Those are retained energy, projectile or bullet composition, and target composition.
Increasing retained energy downrange has been a key pursuit of firearms designers from the arquebus to the .408 Cheytac.
There are three basic ways to increase retained energy downrange. You can have a bullet that flies better. Bullet designers today focus on this. You can launch a heavier bullet at the same speed. And you can launch the bullet faster. Combining all three is the most effective but eventually you run up against constraints.
One of those constraints has been the ability of practical firearms to safely contain the amount of energy released to launch the bullet. Energy in modern firearms is released by burning a propellant (gunpowder) inside the cartridge case. The expanding gases from the burning of the powder create pressure to push the bullet out of the cartridge case and through the barrel. Too much energy causes too much pressure and bad things (like guns exploding) happen. That is why the barrel manufacturers have a key role in making higher chamber pressure weapons a practical reality. The energy (which translates to chamber pressure) is contained by the combination of the cartridge case and the weapons chamber. The energy is released by pushing the bullet down the barrel but the energy must be safely contained while that occurs.
If hybrid cases and firearms designed for them become practical in the civilian market, then we will be able to shoot further and more effectively than we can today. Historical trends say that it will happen but it will likely happen slowly. Long-range shooters will likely go first as they have in the past with “wildcat” magnums. Then, it may trickle out to more widely used weapons.
I am betting it will happen. The entire history of the firearms industry is about chasing the combination of a better and heavier bullet traveling faster.