The development of the .22 rimfire cartridge: Part 2
by Tom Gaylord
Writing as B.B. Pelletier
This report covers:
- Maynard tape primer
- .22 Long
- Rifling twist rate
- Why change the twist?
- Time of flight
- Inuit and the .22 Long
- .22 Extra Long
- The big change
- Smokeless powder
- Smokeless powder
- Smokeless powder
- The bleeding obvious
- A lot more to tell!
- Not even halfway!
Maynard tape primer
A reader asked about toy caps last time and I said I would show some roll-type percussion caps that were used in the Civil War. The Maynard tape primer was a mechanism that held a paper roll of percussion caps and fed them over the nipple when the gun was cocked. It actually worked and was just one of several automatic priming systems that were just ahead of the metallic cartridge era.
The Maynard tape primer fed percussion caps automatically as the gun was cocked. It could be incorporated into the design of the gun or added on.
I ended the first report with Smith & Wesson’s launch of the .22 Short in 1857. At first it was just called a .22, but the introduction of the .22 Long in 1871 caused them to rename it the Short after that time. I didn’t mention it in Part 1 but the chamber pressure of the Short cartridge as it’s loaded today is 24,000 psi, and the bullet diameter is 0.225-inches.
Let’s now spend a little time with the .22 Long.
The .22 Short has a case that’s 0.421-inches long. The 29-grain bullet stretches that to 0.695 inches. The .22 Long has a case that’s 0.613 inches and an overall length of 0.888 inches. It uses the same heeled 29-grain conical bullet that’s found in the Short, which makes us wonder — why?
It may be easy to see why a manufacturer would want to stretch the case. Obviously they were going for more velocity. The velocity of the Long is a little faster — 1,215, compared to 1,105 f.p.s. for the Short, as they are loaded today. But those velocities are with modern smokeless powder. When the Long came out all .22s were still being loaded with black powder. The longer case meant more powder could be packed inside, and that was at a time when the volume of gunpowder mattered more than it does today.
When the Long came out it was a more powerful cartridge. Gunmakers lost no time chambering their guns for it and, usually, if a gun accepted a Long, it would also function with a Short. The actions in those days were all mechanical, so feeding wasn’t a problem. However…
Rifling twist rate
Now you have to learn about the rifling twist rate. The .22 Short cartridge has a twist rate of one turn (the bullet makes one complete rotation on its axis) in 24 inches (1:24). However, some guns chambered for it have been rifled with 1:21 and 1:22 twists. When the Long came out its specified twist rate was 1:16. Remember, they were stabilizing bullets propelled by black powder, so the high velocities you see with cartridges today weren’t happening. Black powder develops more velocity the longer it burns inside a barrel, so the longer the barrel the faster the velocity for a given bullet. But black powder does not generate the kind of velocity that smokeless powder does.
Why change the twist?
Both Long and Short cartridges had an identical 29-grain heeled conical bullet. The Long shot faster than the Short with black powder, so why did they increase the twist rate? The higher velocity would have increased the spin rate on its own. Everything we know about twist rates says if the bullet is stable with a 1:24 rate, then 1:16 would be too fast for the same weight bullet. Now it’s time for us to think in the 4th dimension!
Time of flight
If what I have said so far is true, then why are there two different twist rates? Well, a couple things come to mind. First, the difference in velocities was not that great when the powder in the cartridges was all black. The Long bullet would have been faster in a given length of barrel, but not as much as you might think. A Short bullet might exit a 24-inch barrel at 850 f.p.s. and a Long bullet might exit at 925 f.p.s. That’s the kind of difference we are talking about. But…
The faster the bullet spins on its axis, the longer it remains stable in flight. The longer it remains stable in flight, the greater the distance at which it will be accurate. Think of a football being thrown with a smooth spiral pass. It goes much farther than a “dying duck” (a flubbed pass that turns end over end).
The .22 Short bullet might be stable long enough to travel 100 yards with good accuracy. The .22 Long bullet, however, might go another 50-60 yards with good accuracy because of its faster spin. In the 1870s and 1880s men were shooting .22 Shorts at 100 yards in offhand schuetzen matches. We have difficulty envisioning this today, but in its day the .22 Short was considered a capable cartridge. The Long was even more capable. And that might have led to the strangest thing of all.
Inuit and the .22 Long
When the .22 Long came to market, apparently a number of them were purchased by Inuit people for dispatching game. I mean harvesting, rather than hunting. I’m talking about killing large animals like musk ox and even polar bear, not to mention seals with this diminutive cartridge. My friend, Earl McDonald (Mac) told me this, and I did some research to discover he might have been right. This isn’t a subject that has a lot written about it. At any rate, apparently the reason CCI still makes the .22 Long cartridge is primarily to satisfy the demand in Alaska and Canada, where the guns that are chambered for the .22 Long are considered tools, no different than knives and axes.
PETA and other animal rights organizations are taking down websites all over the internet where this information once resided, so the trail is growing cold, but perhaps a Canadian reader or someone living in Alaska can shed some light on the subject? At this point I have to regard it as an urban legend, though the .22 Long cartridge is still being made by CCI for no other good reason that I can determine. I just bought some while researching this series. And, guns made today that will chamber a Long Rifle cartridge will also chamber a Long, though it may not function through most semiautomatic actions. So — who really needs the .22 Long?
How important is it that your .22 rifle will handle Short, Long and Long Rifle cartridges? About as important as the fact that there is a lightbulb that was turned on in 1901 and has been illuminating for 117 years! Nice to know, but not that important to you. Your lightbulbs still burn out regularly, plus you want more than 4 watts of illumination. The .22 Long turned out to be just an Edison bulb in the development of the .22 rimfire cartridge. And, by the way, the chamber pressure of the modern .22 Long is 24,000 psi and its heeled bullet is 0.225-inches in diameter — same as the Short.
.22 Extra Long
Huh? You made that up, BB. What is the .22 Extra Long?
Well, it was launched in 1880 and died a swift and quiet death. I don’t know if it even made it into the smokeless era. It had a 40-grain lead bullet that was 0.225-inches in diameter, so I’m thinking it was heeled. The rifling twist rate was 1:16. Guns made for it are collector’s items but any ammunition you might find is also collectible, so this gun either isn’t being shot today, or somebody is doing something they shouldn’t. That’s because the metallurgy of the guns would be for black powder, which is generating 12,000 psi or less.
The big change
When the .22 Long Rifle cartridge came to market in 1887, everything changed. The Long Rifle had a case that was/is 0.613-inches long. That’s identical to the .22 Long case. But the overall length of the .22 Long Rifle cartridge stretches to 1.0-inches overall, instead of the 0.888-inches of the Long. A 40-grain heeled lead bullet makes the difference, and even with black powder, the Long Rifle cartridge got that bullet up to 950 f.p.s at the muzzle, in rifles with longer barrels. That heavier bullet made a big difference in killing effectiveness! The twist rate was 1:16. Are you starting to see a pattern?
So, in 1887 there were the .22 Short, .22 Long and .22 Long Rifle cartridges on the market. Guns could be chambered for just one or for all three of them. My Winchester Winder Musket (specified by Army Col. Winder and designed by Winchester) that’s based on the Winchester Low Wall falling block action of 1885 is chambered in .22 Short. When the government bought these rifles to use for marksmanship training they specified the Short chambering. But the same rifle was also chambered for the .22 Long Rifle. Today, shooters go for the Long Rifle model that will shoot all three cartridges. Collectors tend to like the one that’s chambered for the Short.
The Winder Musket is a single shot target rifle that’s based on the Winchester Low Wall action of 1885. This one is chambered for .22 Short.
Left to right — .22 Short, Long and Long Rifle.
Smokeless powder had already been invented in France by the time the Long Rifle cartridge came out, but it wasn’t until the late 1890s that .22 rimfire cartridges were first offered with that powder. The black powder cartridge loadings, along with some semi-smokeless cartridges (part black, part smokeless) continued in production until the 1930s. Target shooters favored them for many years, so there must have been an advantage.
The bleeding obvious
At this time in history, all three cartridges sold for different amounts. The .22 Shorts were cheapest and .22 Long Rifle cartridges cost the most. When making a purchase decision people factored ammo costs into the life cycle support costs of the gun.
Today there is virtually no difference in the price of a Short versus a Long Rifle. That gives buyers no good reason to buy the Short, and gunmakers follow suit.
A lot more to tell!
I’m just getting started on the .22 Long Rifle cartridge. Besides the changeover to smokeless powder, there were priming changes for all three cartridges that had huge affects on the longevity of the firearms in which they were used. And there are the high speed rounds, the ultra high speed, shot cartridges and other developments.
The chamber pressure for a modern .22 Long Rifle cartridge is 24,000 psi and its heeled bullet is 0.225-inches in diameter — the same as the .22 Short and .22 Long. The reason I’m telling you this is because there is about to be a change.
Not even halfway!
Think the rimfire cartridge development is finished? Not a chance. The next cartridge we will look at is the .22 Winchester Rim Fire or WRF. No, it’s not the .22 Magnum. It’s a non-magnum cartridge that uses a bore-sized non-heeled bullet for the first time. And that is another story.