#Trajectory

There are a lot of new, first-time gun owners out there, and I thought I’d take a moment to make ballistics visualized to help new gun owners with explaining how ballistics work with an easy-to-see and do object lesson. This article isn’t exactly meant for our faithful readers that are already aware of how ballistics work, but they’re certainly free to comment if I’ve missed anything or if they have other suggestions on how they explain the topic. Without further ado, if you’ve recently joined the masses in exercising your right to own firearms and you’d like to know how to get your bullets on target, here are some things to consider.

Oh yes, it’s that time. The 10mm Automatic, what hasn’t been said about it? Well, a decently sourced article about its history*, maybe, but that’s for another time. Right now, we’re considering the 10mm Auto (or 10mm Norma as it’s more prim and properly called) as a personal defense weapon and submachine gun caliber. The 10mm was designed in 1980 by Swedish company FFV Norma AB with input from Jeff Cooper as the most powerful and capable automatic handgun round of its day, but will that extra power pay off when pushed beyond its design limits into the 50-300m range, at least according to the JBM Ballistics calculator?

If the 5.7x28mm FN is the first successful modern PDW round, then the 4.6x30mm HK is the second, and its biggest rival. German firm Heckler and developed the microcaliber 4.6mm in the 1990s as a response to a NATO solicitation for a Personal Defense Weapon, to which they submitted their new HK PDW (later MP7) chambered for the new round.

We’ve discussed a lot of different rounds in this series so far, but today we’re going to discuss a round that actually has a shot of being adopted (at least in some form) by the United States military as a next-generation small arms ammunition configuration. That round is the .264 USA, developed over the past few years by the Army Marksmanship Unit (AMU).

After World War II, the nations of the world retired to lick their wounds and rebuild, but their arms engineers also began thinking about the next war. The war have brought forth a storm of new technologies and inventions, and one of the most significant in the field of small arms was the finally mature assault rifle in the form of the Nazi-developed “Sturmgewehr”, and its intermediate 7.92x33mm Kurzpatrone cartridge. One nation that took notice of this new weapon and its ammunition was the newly reconstituted Czechoslovakia. That nations engineers quickly took to copying and improving the 7.92 Kurz caliber, producing by the early 1950s a short-lived but unique round called the 7.62x45mm Kr.52, or more popularly the 7.62×45 Czech. The 7.62×45’s projectile was a near copy of the Kurzpatrone’s stubby, steel-cored one, but its case was much longer, while being slightly thinner, and having a greater internal volume. This gave the Czech round an additional 250 ft/s muzzle velocity versus the German 7.92×33 when fired from the barrel of the rifle that was designed alongside it, the strange but wonderful vz. 52.

At this point we’ve looked at the data for seven intermediate calibers currently on the market, each of which is – one way or another – influencing the discussion around the question of what next generation military rifle caliber will be. Those rounds were: The 5.56mm NATO, the 7.62x39mm Soviet, the 6.8x43mm SPC, the 6.5x38mm Grendel, the .300 AAC Blackout, the 7.62×40 WT, and the .25-45 Sharps. Initially, I intended for this series to be limited to just these seven, and I picked them as a cross section of different concepts and schools of thought regarding the intermediate caliber problem. Now, however, I have decided to expand this discussion to other calibers, including the latest developments outside the West. I figure I’ll just handle the extra clunk this introduces by breaking up the final comparative discussion into segments, that way all the data is presented clearly, and there are more posts for my readers to chew on. Everyone is happy.