While we’re on the topic of burning powder, I’d like to note that we’re talking about really high levels of pressure. To put things in perspective, if you ride a spiffy racing bike, you know the tires are really hard because they’re pumped chock-full of air—somewhere between 80 and 130 pounds per square inch of air pressure. While that seems like a lot, it’s nothing compared to even a low-powered ammunition cartridge. The .45 ACP load operates at pretty low pressure compared to other handgun cartridges, and even those generate between 15,000 and 20,000 pounds of pressure per square inch! Rifle cartridges like the .223 Remington used in AR-type guns hover around 55,000 pounds per square inch. By my math, I figure that’s about 611 racing bike tires crammed into that tiny little rifle cartridge.