Friday, July 11, 2008

Reader questions about firearms and recoil - UPDATED



(EDITED TO ADD: As a result of feedback from readers, asking questions I hadn't answered, I've added a few paragraphs on body size and shotgun position as factors in felt recoil. I've also modified some sentences here and there to make them easier to understand.)

A question from Steve in my first post on Firearms For Home Defense, earlier this week, and two questions from other readers via e-mail, were the inspiration for this post. Both e-mails were from readers who confessed that they were put off at the thought of handling the recoil of a shotgun, and asking me if they were unduly concerned about this.

No, friends, you're certainly not wrong to be concerned. However, I think a large part of the perceived problem with recoil is due to the exaggerated stories told by shooters, and "ooh, scary!" video clips showing strong men hammered by heavy-recoiling firearms. I'm sure many of you have seen this video clip of shooters firing an A-Square rifle in caliber .577 Tyrannosaur, which is a ridiculously powerful round (of which we'll say more later):





Or this one of a clearly untutored gentleman, firing a specially-built handgun chambered for the .600 Nitro Express cartridge, normally used in heavy rifles to hunt elephant (warning - language alert!):





It's no wonder some are put off, watching those! However, in both cases, with a little training in how to hold the weapon and brace themselves correctly to accommodate the recoil, there would have been no drama whatsoever. Did you notice the last shooter in that clip of the A-Square rifle? He handled it without any trouble, because he was positioned and braced correctly to absorb and control the kick.

Let's start by defining what we're talking about. Recoil is not the same as free recoil. Recoil is the backward momentum imparted to the gun when it's fired. Free recoil is the momentum actually transmitted to and felt by the shooter. This is not the same as the momentum imparted to the gun. I'm not going to go into the technical and mathematical minutiae here. For a more scientific discussion of recoil, see the Wikipedia article on it, as well as two articles on calculating recoil. To better understand free recoil, its Wikipedia entry is a good resource.

So, we're going to talk about "free" or "felt" recoil - the push or shove that you, the shooter, experience when you fire a round. This is affected by many factors: the weight of the firearm (which helps to absorb the recoil), its shape, the way in which you hold it, and the way in which you brace yourself to absorb the recoil impulse. Let's look at each in turn.

The weight of the firearm is a critical element in free recoil. In a nutshell, all other things being equal, the heavier the firearm, the less free recoil will be imparted to the shooter - it'll be "soaked up" by the gun itself. To illustrate, let's look at a moderately powerful handgun round, the .357 Magnum. Let's take a mid-range load in that cartridge, a 158-grain bullet propelled at a measured velocity of 1,267 feet per second (fps) out of a 4" barrel. There are many handguns available chambered for this cartridge. In the chart below I've listed four from Smith & Wesson. The Model 627 is an N-frame, very large revolver. The 686+ is an L-frame, medium-size revolver. The Model 60 is a small J-frame revolver, often carried in the pocket. The Model 340 is also a J-frame, the same size as the Model 60, but made of ultra-light-weight scandium alloy rather than steel. Note the different weights of these revolvers, and the effect this has on free recoil when firing exactly the same cartridge through each one. (Click the chart for a larger view.)




I've fired every one of these revolvers - and I'm here to tell you, the Model 340 with full-house .357 Magnum ammunition just plain hurts! After three rounds, my wrist was saying to my brain, "Hel-loooooo, carpal tunnel syndrome!" I had shooting, stabbing pains in my wrist and up my arm, and I refused to fire any more. This is one gun I won't be buying - and if I'm ever given one, rest assured I'll only shoot much-lower-powered .38 Special ammunition in it!

The same consideration applies to shotguns. Let's look at four models of 20ga. shotguns from Mossberg. The Model 54241 is a turkey gun; the 50136 is a typical field gun; the 54132 is a Bantam model for smaller-statured shooters, and my personal recommendation as an excellent home defense weapon; and the 57110 is what Steve wants to buy, an even smaller youth model. The free recoil is calculated for each model using the same round: the Remington 20ga. 2¾" #3 buckshot round, product code 20B3, which is a typical hunting or self-defense load.




You'll note that since even the smallest and lightest of these shotguns isn't all that light, free recoil still remains manageable: but it's nevertheless well over a third greater in that gun than in the heaviest shotgun. That's what you'll feel against your shoulder when you fire it. For any given round, all other things being equal, the heavier the firearm, the less free recoil you'll experience.

Of course, all other things aren't always equal. I've (unfortunately) encountered many "macho men" who sneer at the "puny" 20ga. round, asserting that only a 12ga. is suitable for defensive use, and arguing that its recoil is no worse than that of a 20ga. Neither assertion is true, of course. As I pointed out in my first post on firearms for home defense, the 20ga. has more than enough energy, enough "punch", to do the job. As for the difference in recoil, this is very often a function of the weight of the gun.

I used a standard Remington load in the 20ga. comparison above. Let's take the equivalent standard Remington load in 12ga., the 2¾" 00 Buckshot round, product code 12B00. In shotguns of equal weight, the 12ga. load will produce about 26.5% more free recoil than the 20ga. round - every time. Using my recommended Mossberg Model 54132 as the 20ga. shotgun, it weighs 6.5 pounds. A 12ga. shotgun, firing the 12ga. Remington load, would have to weigh 8.22 pounds if its free recoil were to be reduced to the same level as the 20ga. load in the 6½lb. Model 54132 - a weight gain of 1.72 pounds, or 26.5%. You see how the weight gain matches the difference in free recoil? The percentages are identical.

So, the weight of the firearm is one thing that can soak up recoil. Unfortunately, to soak it all up, your gun would be unmanageably heavy. By adding weight, I could reduce the free recoil of that 20ga. Remington buckshot load to no more than a .22 rimfire round: but by then the shotgun would weigh 500 pounds! Try carrying that around the house - much less putting it to your shoulder and lining it on a target!

Another factor in free recoil is how you're holding the weapon. If your grasp, stance, etc. are correct, your body will absorb the recoil much more easily, and you'll feel it more as a push than a punch. If you want to illustrate this (which I don't recommend, by the way!), deliberately hold your shotgun loosely against your shoulder, rather than tightly, and touch off a round. The gun will kick back hard into your shoulder, because it's not properly braced, and you may have a nice bruise there next morning. On the other hand, if you're holding the gun tightly braced in your shoulder pocket, it won't move back much at all, and you won't have any nasty reminders next morning.

That's one of the reasons why getting competent instruction is so important. I know how to hold a shotgun correctly, but I can't just tell you in words - I have to show you. That's why I haven't gone into detail about it on this blog. I don't have video instructions I can post to show you what I mean, and I won't be there when you try it, to point out your mistakes and show you a better way. For this sort of thing, a good instructor is indispensable. Sure, there are those who've learned to shoot without instruction. You can generally tell who they are when you see them shooting! They've acquired bad habits, and it shows in their results. Also, when it comes to heavy-recoiling firearms, they tend to get bruised a lot! Go back and review that clip of people firing the A-Square rifle. Notice the different stances they use, and compare them to the last man to shoot, who did it properly. See the difference? By holding the rifle correctly, and bracing himself correctly, he fired it with no trouble at all.

Another factor in felt recoil is the shape and size of the butt-plate or recoil pad of your shotgun. If a given force is transmitted through a very small surface area, it can penetrate a lot deeper, or hurt a lot more, than the same force transmitted over a wider area. A good example is a hammer and a nail. By striking the top of the nail with the hammer, it's driven into a plank of wood. However, striking the wood with the hammer itself, using the same force, wouldn't produce any penetration at all. The broad, flat head of the hammer won't go through the fibers of the wood in the same way that the sharp point of the nail does, even though the same force is used and the same blow struck each time. The wider the surface, the more "spread-out" the force becomes, and the less immediately it acts at any point on that surface.

The same applies to a shotgun stock. The free recoil is transmitted through the recoil pad at the back of the stock. The more of this pad that's in contact with your shoulder, the more of its area is available to absorb recoil. The larger the pad, ditto.

The recoil pad itself is another factor. It's designed to soak up a certain amount of free recoil, absorbing it rather than transmitting it to your shoulder, acting a bit like a shock-absorber in a motor vehicle. The standard recoil pads supplied by most manufacturers are OK, I guess, but there are better ones. In particular, Limbsaver and Kick-Eez make very superior products, offering a vast improvement in recoil absorbtion over older-technology pads. I often recommend that people buy one and fit it to their shotguns. Both companies make pads in different sizes, so you might find one of the right size "out of the box": or you can buy one that's close, and have a gunsmith grind it to fit your gun. I've used both methods, and both have produced equally good results. I highly recommend both firms' products.

Also, consider what the recoil pad is resting upon. You should seat the shotgun firmly in the "shoulder pocket", formed when you lift your elbow horizontally to the ground as you take a firing grip on the shotgun. If this is done properly, the butt of the shotgun rests against muscle and bone, and is firmly braced. However, if improperly positioned, the shotgun is resting against soft flesh - for women in particular, it may rest on the upper slopes of their breast. This tissue is very sensitive to bruising and shock. Ladies, it's absolutely critical to avoid resting the shotgun butt on it! You will regret it, both immediately and for the next few days! Again, this is something that a competent coach can correct before it becomes a problem - but I can assure you that it's a mistake you'll only make once! The tragedy is that some women, having made that mistake, blame the shotgun itself for the problem, and never shoot one again. It's a problem that's easily remedied with a little coaching assistance.

(One important factor for women is the possible presence of breast implants. These can be - and have been - ruptured by the recoil of shoulder-fired weapons. If you have implants, particularly larger ones, be very, very careful to assume the correct shooting position, and make sure that the edge of the implant is well away from the recoil pad! It might be a good idea to check with your physician, just in case.)

There's a final factor to consider in how recoil is felt - the weight, size and build of the shooter. Basically, the same free recoil force will be exerted by a given gun and round, irrespective of who shoots it. A heavier and/or larger and/or stronger person will feel that free recoil less than a a lighter and/or smaller and/or weaker shooter. What a 240lb. person can tolerate may be far more than will be comfortable for a 140lb. person. The extra 100 pounds of body weight available to absorb or "soak up" the free recoil makes a big difference! (This is one reason why I think many men assert that a 12ga. shotgun has no more felt recoil than a 20ga. Their much greater size and weight than many women means that the approximately 25% greater recoil impulse of the larger round - given the same weight of gun - isn't readily detectable when they shoot the two rounds. For them, there isn't much discernible difference. However, someone smaller and lighter will most certainly feel it!)

So, free recoil is affected by the weight of your weapon, the way you hold it, the surface available to transmit recoil, the quality and efficiency of the recoil pad between you and your gun, and your own weight and build. All those factors have to be taken into account.

I've found that by using a gun of reasonable weight for the caliber or cartridge concerned (i.e. not too light), and making sure that the gun fits the shooter properly (i.e. the buttstock is the right length for their arms), and making sure that they hold it and position themselves correctly, and sometimes by fitting a better recoil pad, any shooter - even a ten-year-old child - should be able to handle a 20ga. shotgun with no trouble at all. Certainly, the last shooter I trained seemed to enjoy herself. You can read her reactions on her blog. She fired birdshot and slug rounds, having (as far as I know) never fired any long gun besides a .22 rifle, and managed them perfectly well. As for the heavier-recoiling 12ga. shotguns, they too are perfectly manageable by a shooter who knows what he's doing: but I find it's often easier if shooters grow accustomed to the 20ga. first, and become fairly competent. After that, they can handle almost anything. It's simply a matter of applying what they've already learned.

Oh - and that .577 Tyrannosaur rifle you saw people trying to shoot in the first video clip? Well, let's look at its free recoil. According to the manufacturer's data, the rifle weighs 13 pounds; the bullet weighs 750 grains; and its muzzle velocity is 2,460 feet per second, delivering muzzle energy of 10,180 foot-pounds. (Compare that to the 20ga. buckshot load, noted above, which delivers 1,496 foot-pounds, or the 12ga. buckshot load, which churns out 1,887 foot-pounds!)

Plugging these figures and the powder charge into my calculator, that rifle's free recoil energy is 169.51 foot-pounds! That's eight and a half times more than the 20ga. round in a Mossberg Model 54132. Can I have a communal "Ouch!", please?

The late, great Col. Jeff Cooper had this to say about the .577 Tyrannosaur:

We were fascinated ... to examine the "577 Tyrannosaur" from A Square. This piece is designed to end all discussion about stopping power. It is a bolt-action (1917), 3-plus-1, 13lb rifle which fires a 750-grain bullet at 2460 feet per second. It is said to be the first sporting rifle cartridge that "breaks the 10,000 foot-pound barrier".

In my opinion this is a definitive example of a piece which is made to own rather than to shoot. It is not at all clear that it will kill an elephant or a buffalo or a hippo any better than a well placed hit from a 470, and, of course, it will not do anything with a badly placed hit except annoy the recipient. As I see it, this combination should be referred to as the "577 Dundee". You keep it available in your armory so that when people start talking about the power of their rifles you can break yours out and say, "That's not a rifle. THIS is a rifle!"




Peter

2 comments:

Steve said...

BRM,

Thanks for your additional thoughts!! I am little concerned with recoil, and more concerned about portability and appearance.

I like the shorter 20 ga model 57110, as I think it makes getting around corners and through doorways easier. The downside of this I missed was it is 1 1/4 lbs lighter than the 54132.

I really like the idea of wood stock and pump - it sure looks more friendly should I have to talk to a judge or jury!!

Thanks again for making the internet a better place!

Steve

zeeke42 said...

One factor in felt recoil that you left out is the effect of the gun's action. A semi-auto has less felt recoil than a pump or revolver, due to the fact that some of the recoil energy is used to operate the mechanism.

This isn't really a factor for your series, as autoloading shotguns add cost and complexity that you're trying to avoid.