When it comes to the discussion of recoil, the usual issue is how to reduce it. Recoil, or more specifically the anticipation of recoil, is the usual cause of flinching – a shooter’s worst enemy. Flinching occurs when a shooter anticipates recoil and, often unconsciously, jerks the trigger. Reducing recoil can often aid the shooter in concentrating more on the fundamentals of marksmanship and less on reacting to the gun’s recoil.
On more practical terms, recoil can get downright unpleasant. Heavier calibers can produce enough recoil to make the shooting experience less than fun. Reducing recoil can put the fun back into a trip to the range.
Reducing recoil also reduces wear and tear on the gun, extending its life. For semiautomatic pistols, less recoil means slower slide velocity, and less battering of parts.
In some circumstances you might want to increase recoil. For example, more recoil might help the gun to cycle more reliably. Reliable cycling can also be regulated by spring strength in semi-automatic pistols. For pistols with compensators, more recoil, or to be more specific, more gas volume, might be desired to make the compensator work more effectively to reducing muzzle climb. See here for an article on gunpowder and compensator function.
Several factors influence recoil, including bullet weight and velocity, and gun weight and design. Another factor that affects recoil dramatically is the burning rate of the gunpowder. Handloaders have a real advantage here since they can select a gunpowder with a desired burning rate to regulate recoil.
All else being equal, specifically the same gunpowder and charge weight, lighter bullets produce less recoil. An important feature of this axiom is that the gunpowder is the same for both bullets. Using different gunpowders for heavy and light bullets changes the whole issue on recoil. With different gunpowders you could end up with more recoil for the light bullets than for the heavy bullets. The gunpowder issue is discussed in more detail farther down this page.
The heavier the gun, the less the recoil. This assumes the same gun design. Different gun designs can change the felt recoil (see below). Adding weight to a gun can reduce recoil. One common addition to a 1911 pistol is a full-length recoil spring guide rod to replace the common, short version. The weight of the full-length guide rod is ideally placed as well, being at the front of the gun, which helps to dampen muzzle flip. Some gun makers offer full-length guide rods as standard equipment on some models. Some parts manufacturers also offer tungsten full-length recoil spring guide rods. Tungsten is much heavier than steel and adds approximately one more ounce than a steel full-length guide rod.
One concern that competitive shooters have is whether the extra weight, especially of the tungsten guide rods, at the front of the gun makes it feel sluggish when transitioning from one target to another. Most (but not all) shooters don't think so, and the author has not found that to be the case either. A more experienced opinion can be found at Brazos Custom Guns.
Gunpowder Burning Rate
The burning rate of a gunpowder can affect how much recoil is produced. Generally speaking, faster burning gunpowders produces less recoil than slower burning gunpowders.
Different gunpowders burn at different rates. People often put them in categories like fast, medium, and slow. However, there are no clear boundaries for these categories since the burning rates form a continuum from fastest to slowest. Burning rate charts can be found at several locations on the web (for example: Hodgdon, Ramshot Powders, Reload Bench, Vihtavuori Loading Guide). However, there is no clear agreement on the ranking of many gunpowders because the ranking for any given gunpowder varies. Therefore, burning rate charts should be used as guides and not as gospel. Never estimate gunpowder charges based on their ranking in a burning rate chart. Always follow a loading guide.
In very simplistic terms, here is the logic behind how the burning rate of a gunpowder influences recoil.
1. Faster burning gunpowders reach peak pressure more quickly than slower gunpowders. Consequently, a smaller charge weight is required for faster gunpowders to reach a given velocity.
2. By inference, slow gunpowders require more of it (usually weight) to reach a given velocity.
3. More gunpowder means more gas. More gas produces more recoil.
4. Therefore, slower gunpowders require more of it to reach the same velocity, and they produce more gas which results in more recoil.
Okay, let me put that in English. When comparing gunpowders with different burning rates, the faster burning gunpowder will produce less recoil when propelling the same bullet to the same velocity. The critical feature is that the weight of the gunpowder required to achieve the same velocity is less for the faster burning gunpowder.
Here's an example to illustrate this point. Let’s say you have two gunpowders, a “fast” one and a “slow” one. Let’s say that the fast gunpowder requires 5.0 grains to propel a 130 grain bullet at 1000 fps, and that the slow gunpowder requires 6.0 grains to propel the same bullet at the same velocity. The fast gunpowder should produce less recoil.
I conducted a series of tests with 8 different gunpowders in the 38 Super. Their burning rates spanned a wide range as shown in the table based on Hodgdon's rank in their burn rate chart. Titegroup was the fastest burning, Longshot was the slowest. Their charge weight required for a given velocity also varied considerably (see below).
Remington 115 grain JHP bullets were loaded at 1.245 inches OAL. Three to four charge weights were loaded for each gunpowder. Rounds were fired from a 5 inch Kart barrel in a custom Para Ordnance double stack pistol. Recoil was measured by gun movement in a Ransom Rest.
Each gunpowder showed a unique recoil profile, as shown in the figure below. Faster gunpowders (lower lines) produced less gun movement than slower gunpowders (upper lines) for the same velocity.
Each dot indicates a charge weight which is an average of 10 shots. Thus this plot shows data from 250 rounds. AA7 = Accurate Arms No. 7; LS = Longshot; PP = Power Pistol; TG = Titegroup.
Analysis showed that a gunpowder's charge weight for a given velocity predicted how much recoil it produced. The figure below shows the gunpowders in their rank order for recoil and their charge weight to achieve 1275 fps velocity. Gunpowders that required more charge weight for 1275 fps also produced more recoil (compare with the plot above). The exception was N320 and Titegroup. Titegroup produced more recoil than N320 even though it's charge weight was slightly less than N320.
AA7 = Accurate Arms No. 7; LS = Longshot; PP = Power Pistol; TG = Titegroup.
Ultimately, you have to test for yourself which gunpowder(s) will produce the recoil impulse that fits your needs, but the data presented here show that charge weight is a good criteria for making that selection. Check your reloading manual for charge weight/velocity information.
If you are shooting a pistol with a compensator, the more-gas-equals-more-recoil rule gets turned around. Compensators deflect gas upward to reduce recoil. In this instance, more gas for the same velocity results in reduced muzzle rise. See the Gunpowder and Recoil article for details.
Light and Fast versus Heavy and Slow
There is often discussion among competitive shooters about the type of recoil characteristics that they prefer when it comes to selecting a bullet weight. The discussion revolves around the light-and-fast type of recoil versus the heavy-and-slow type of recoil. This refers to light bullets moving at fast speeds versus heavy bullets moving at slow speeds.
In this example let's neurtalize the gunpowder issue so it doesn’t get in the way of this discussion, and use the same gunpowder for different bullet weights.
Different bullet weights can produce different subjective experiences of recoil when both are loaded to similar power levels. For instance, lets say you’re trying to decide between your favorite 115 grain bullet and your favorite 147 grain bullet for an upcoming competition. Let’s say that you have to achieve a Power Factor of 125 in order to comply with the rules (see the Box for an explanation of Power Factor). A 115 grain bullet has to travel at least 1087 feet per second (fps), and a 147 grain bullet has to reach 851 fps to reach a 125 Power Factor. So, the light bullet will be traveling fast and the heavy bullet will be traveling slow.
Generally speaking, the felt recoil of the lighter bullet feels “snappier” and harder than the recoil from the heavy bullet. It feels this way because the recoil event of the lighter bullet occurs over a shorter interval than the recoil from the heavier bullet (a more intelligent explanation of recoil can be found at: http://en.wikipedia.org/wiki/Recoil). It’s a product of mass and acceleration. The lighter bullet has less mass but more acceleration. Many people feel that the heavier bullet has less felt recoil because the recoil event is spread out over a longer interval. Depending on the gun and cartridge, the difference in recoil characteristics can have a significant impact on how the gun handles. Ultimately, individuals differ on which recoil experience they prefer, fast or slow.
Bullet Weight, Power Factor and Recoil
Do different bullet weights produce the same amount of recoil when producing the same power factor? Recoil was measured as noted above.
Four different bullet weights were tested in the 38 Super, 115, 130, 147 and 180 grains. The same gunpowder was used (Ramshot Silhouette), as were multiple gunpowder charge weights for each bullet weight so that linear regression could be applied to the analysis. Having multiple data points for a single bullet weight allows one to calculate recoil for a specified velocity. In this case it was the velocity required for a bullet weight to achieve the desired power factor. For example, a 115 grain bullet must achieve 1087 fps to achieve a 125 power factor. A 147 grain bullet must achieve 851 fps to make that same power factor (see a power factor table here.).
The test gun was a Para Ordnance high capacity pistol with a 5-inch Kart 38 Super barrel. Bullets were: 115 grain Hornady FMJ RN, Winchester 130 grain FMJ RN, Hornady 147 grain FMJ RN, Nosler .357 caliber 180 grain JFP. All bullets were seated to the same overall length of 1.245 inches.
Results showed that heavier bullets produced less recoil (measured as gun movement) for the same power factor. Data in the figure shows gun movement for power factors 125 and 165.
Recoil and Reliable Functioning
An issue when developing light loads for semi-automatic pistols is that there might not be enough recoil force to ensure reliable cycling. This can be corrected by installing weaker springs. In the typical 1911 type pistol, two springs influence slide movement. The obvious one is the recoil spring. But the hammer spring also resists slide movement.
The usual factory strength of a 38 Super recoil spring in a Government Model (5 inch barrel) 1911 pistol is 14 pounds. My approach to light load development has been to retain the 14 pound recoil spring and make sure all my light loads will cycle with that spring weight. But some folks prefer lighter loads, or lighter springs. Installing a weaker recoil spring can allow the pistol to cycle with loads that won’t operate a 14 pound spring. Most 38 Supers will run fine with a recoil spring as low as 10 pounds in strength. But remember that the slide must have enough energy when moving forward to strip a round from the magazine. If the recoil spring is too weak, it can’t do that. A 10 pound spring will usually feed rounds just fine, but that might not work for every gun for a variety of reasons. Keep this in mind if you decide to install a weaker recoil spring.
The weight of the hammer spring is also a factor since it also influences slide velocity. The hammer spring resists slide movement only for the initial phase of rearward slide movement, until the hammer is cocked, whereas the recoil spring resists slide movement throughout its complete movement cycle. The usual weight of the hammer spring for typical factory 1911 guns is 23 pounds. But I know from personal experience that different brand-new 1911s have had very different hammer spring weights, some heavy, some light, so 23 pounds is more like a guideline rather than a rule. I put 19 pound hammer springs in the 1911s I build because that is my personal preference as part of my “trigger job.” This reduced power hammer spring allows the slide to cycle easier with light loads.
The 19 pound hammer spring weight has, in my guns, provided 100% reliable ignition with all pistol primers, including the so-called hard CCI primers. But keep this primer-ignition issue in mind if you decide to install a weaker hammer spring since primer ignition is directly related to hammer spring strength (and the particulars of the components in the fire control system) and your results might differ from mine.
There are several sources for recoil springs and hammer springs of different weights. One place that has a wide variety is Brownells, but your local gunsmith might as well as many other places you can find on the internet.
12-20-12 Added Bullet weight, power factor and recoil section.
4-12-13 Added compensator information and link.
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