CCI Quiet-22

Tuesday, January 31st, 2012

When I read about CCI’s new Quiet-22 ammo, I was reminded of a discussion we had around Ian Fleming and Geoffrey Boothroyd and “silenced” guns.

CCI’s Quiet-22 ammo sacrifices both speed and energy to earn its moniker. By shooting a 40-grain bullet at just 710 feet per second — rather than 1,000+ fps — it produces a “quiet” 68-Decibel report:

CCI’S 710 fps Quiet-22 Ammo only produces 68 Decibels (dB) of sound at the shooter’s ear (compared to 132-139 dB for a standard .22LR). How do we put that in perspective? Consider this: 68-70 dB is the noise level inside a typical family sedan cruising at 70 mph. For additional comparisons, a typical alarm clock ringer produces 80 dB of noise, while a hair dryer can deliver 90 dB. The sound levels at rock concerts can top 115 dB, and a chain saw can hit 125 dB.

OSHA requires hearing protection in the workplace at 85 dB.

Comments

  1. Gwern says:

    I read once that range was a function of kinetic energy, and kinetic energy is determined both by the weight and the speed of the bullet. Hence, if one wanted a particular range, one could use any point on the range between a fast light bullet or a large slow bullet. The fast bullet of course makes noise by its speed, and so is hard to silence; but the large slow bullet is equally quieter.

    Hence, it would be possible to make a long-range bullet which was also quiet if you choose to make it large and slow.

    I thought I also read once of a Russian sniper rifle designed to use just such special ammunition, but I don’t seem to see it in my notes anywhere.

  2. Isegoria says:

    A bullet’s range depends primarily on its velocity and only secondarily on its mass. A longer bullet has more mass per unit of frontal area — it has a higher sectional density — so it loses less velocity to drag. Also, drag is a function of velocity — or, rather, of the square of velocity — so faster bullets decelerate more quickly.

    So, a long, aerodynamic bullet shot at low velocity could retain much of its energy, but it would never have the flat trajectory of a light, high-velocity round. How loud it was would be a function of how much powder (and thus kinetic energy) was involved, whether the bullet crossed the sound barrier, and other factors.

  3. Macadamia says:

    The “new” quiet ammo seems no different than the .22 CB that has been on the market for as long as I can remember, at least 20 years or so. I wonder if CCI is just re-marketing an old product that people are starting to forget about.

    The idea is to eliminate all gun powder from the case and rely entirely on the primer as the propellant. Shot from a rifle it is extremely quiet. From a pistol (Sturm Ruger Mark II in my case) it generates a bit more noise, but still not enough to even warrant the use of ear muffs. Of course it does not cycle the action, but works very well in the urban setting on squirrels that attack my hazelnut and walnut trees.

  4. Othera says:

    It seems like a lot of haphazard information here, though not totally incorrect. There’s no mystery to kinetic energy and projectile physics in general – it’s 1/2mv^2 where m = mass and v = velocity; thus, the same linear increase in mass yields a linear increase in kinetic energy whereas the linear increase in velocity yields an exponential increase in kinetic energy. Velocity wins.

    Now, what CCI has done here is to increase the mass of the projectile and maintained the same velocity. The purpose behind this round isn’t to shoot a flat trajectory, it’s to deliver as much energy as possible while maintaining as silent a report as possible while maintaining credible accuracy. The 29 grain projectile was used in the CB Long. The Quiet-22 uses a 40 grain projectile which will give roughly a 33% increase in kinetic energy delivered upon impact. As long as the report is still very low, that is a *significant* upgrade in the capability provided by a cartridge of this type. Remington has a CBee round, which is 740 fps and 34 grain, if you’re looking for alternatives.

    If you just want a fast, flat shooting round, the .22LR will *never* be the way to go. Your only other real rimfire options are the older Remington 5mm, .22 WMR and .17 HMR, all with various pluses and minuses.

  5. Isegoria says:

    I’m not sure what strikes you, Othera, as “haphazard though not totally incorrect,” but I will note that velocity doesn’t “win” in any meaningful sense, because doubling mass doesn’t, for instance, halve velocity. In fact, the same powder charge will impart roughly the same kinetic energy (not momentum) to different-mass bullets, so doubling mass would divide velocity by the square root of two. If you want to reduce the kinetic energy of a cartridge, the surest way is to reduce the charge — and if you want to increase the energy, you increase the charge.

    Moving up from a 29-grain bullet to a 40-grain bullet — that is, increasing the projectile’s mass by a third — only increases its kinetic energy by a third if you increase the powder driving it by a third, to maintain the original velocity — and that should increase the report.

    Moving up to a heavier bullet without increasing the charge gives you a slower bullet with the same energy. So it does not shoot as flat, but it retains a higher percentage of its energy downrange.

  6. Sconzey says:

    I wonder if one had an army where companies were given greater freedom over their own equipment requirements, whether the tactical and strategic benefits of having a variety of weapons and ammunition types would outweigh the logistical disadvantages.

    In the modern age of electronic stock control, if Walmart manages to keep all their stores stocked with a million different products, one would have thought that many of the old questions of military logistics are now moot.

  7. Armies operate under conditions where modern JIT inventories break down. Conflating the orthodox and the unorthodox, as Sun-tzu wrote, only produces problems. Unorthodox formations of a military like JSOC should be allowed unorthodox selection of equipment. The more numerous orthodox formations should be equipped with weapons that allow procurement with sufficient economies of scale.

  8. Chief Network Janitor says:

    As with all product claims, “the proof is in the pudding.” Is it truly .22 Long Rifle (as opposed to .22 Long, in the case of CB Longs)? Yes, it’s LR. Is it Quiet? Relative to full powered .22 LR, yes, it’s quite a bit quieter.

    I tested the new CCI Quiet-22 rounds with a Ruger 10/22 FS (~16″ barrel). The rounds were manually cycled, as they don’t have the power to cycle most semi-automatic actions. In my testing, the report was similar to the sound levels from .22 Short rounds fired from the same rifle. It’s significantly louder than most pellet rifles, but has quite a bit more power, as well. An average .177 caliber air rifle can produce about 8.6 ft-lbs of energy at the muzzle, using a 7.9 grain pellet traveling at around 700 fps muzzle velocity. These Quiet-22 rounds produce around 45 ft-lbs, or almost half the energy of some full-powered .22 Long Rifle rounds.

    In my own testing, the gold standard in super quiet .22 rounds, is definitely the Aguila Colibri (it’s a half-weight 20 gr bullet, with a 10-shot average of 383 fps muzzle velocity, chronographed on a 16″ barrel; producing 6.5 ft-lbs muzzle energy). In comparison to Colibri, the CCI Quiet-22 rounds are quite a bit louder on the same rifle. However, they also deliver 7 times as much energy to the target, too.

    The Colibri is quieter than most air rifles, but is appaulingly inaccurate from most .22 LR barrels, largely due to its bullet having half the length and mass of the typical .22 LR bullet. Colibri 20-grain bullets don’t stabilize well when fired from a typical .22 LR barrel, due to its average twist rate of 1 rotation per 16 inches of barrel length. In my testing, these lightweight bullets tend to spin wildly from a 10/22, and produce very large (~7.5 inch) 10-shot groups at 20 yards. I’ve read reports of other folks achieving much higher levels of accuracy with Colibri rounds; but I’m deeply skeptical. With repeated attempts, my painstaking measurements consistently produce the same poor results. Without a custom-rifled barrel, perhaps a 1:24 or 1:26 twist, and a careful round selection process (weighing and measuring each bullet), I don’t think one can expect anything closely resembling accurate results with Colibri rounds. But I’d love to be proven wrong, and I’d probably buy the rifle that did it!

    In contrast to the Colibri, the CCI Quiet-22 has double the mass, and nearly double the muzzle velocity. It’s considerably louder, but its 40-grain bullet, and 710 fps velocity make it completely compatible with the normal twist rate of the standard .22 Long Rifle barrel. This is the biggest reason to use these new rounds. Because these are normal sized .22 rounds with 40-grain bullets, they shoot with normal levels of accuracy, out to 50 yards (~.75″ groups). Beyond 50 yards, their lower initial velocity may eventually begin to impair accurate performance downrange, as compared to higher velocity ammunition. In particular, high velocity rounds are generally less affected by crosswinds.

    I noticed that a popular online retailer of ammunition had another user-submitted review of the Quiet-22′s muzzle report. He noted varying levels of report, depending on each barrel length he used during testing. This makes perfect sense. On a shorter (carbine) rifle barrel, if the powder charge is still burning as it exits the muzzle, the gases are hotter and still accelerating into open air. This will produce louder reports. Conversely, on a longer barrel, if the powder charge has been consumed within the length and volume of the bore, the gases will begin to cool and decelerate even before exiting the barrel. This will produce a less noisy report. This is the same principle used in sound suppressors, and even automotive mufflers. Cooler, decelerating gases are quieter when they reach open air. (This is also why a coolant, such as water, can be very helpful in further reducing reports in muzzle-attached sound suppressors).

    In his review, Richard of Attica, NY summed it up very nicely when he reported the following of CCI Quiet-22:
    “Sound levels are very subjective. What is loud to one person may not be loud to another. I tried the CCI Quiet .22 with a 16″, 18″, and 24″ barrel rifle. The discharge sound with the 16″ barrel was typical of a .22 Short. The sound from the 18″ barrel showed significant noise reduction where the noise level was much lower than a .22 Short. The sound level from the 24″ barrel was typical of a BB gun, the bullet hitting the backstop was much louder than the rifle report. The 24″ barrel sound level was consistent with a Aguila Colibri .22, but the CCI Quiet 40gr bullet is much more accurate than the 20gr Colibri. Bottom line: Barrel length is significant for the apparent noise level using the CCI Quiet .22.”

    And this is the one stat that I did NOT see published by CCI. They report an astonishingly low 68 dB report at the shooter’s ear, and 710 fps velocity. However, they did NOT publish the barrel length they used in their testing. I can say that a number of online sources have recorded the sound of a dry-fired weapon at over 100 dB. That “seems” high to me; but I’ve read it from several credible sources, so perhaps it’s true?

    I, for one, would like to know the barrel length and particular rifle selected for CCI Quiet-22′s published muzzle report stat. Some of the very best .22 LR sound suppressors achieve measured numbers of around 112+ dB, using well-known testing protocols. That’s still a far cry from CCI’s claim of 68 dB, isn’t it? Without more information, I’d say it’s reasonable to be skeptical of marketing hype.

    Even so, these new rounds are truly .22 LR. They are quieter than other full-sized .22 LR rounds, and more accurate than their competitors’ miniaturized quiet rimfire rounds. For these reasons, I’m very pleased to see them introduced to the marketplace.

  9. Isegoria says:

    That’s an excellent point about barrel length, Chief Network Janitor. As I understand it, a preposterously long barrel can even “silence” a shotgun — to the level of a car door slamming.

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