Throwback Thursday — Decoding Shotshell Markings to Determine Powder Charge

By Dave Dolbee published on in Ammunition

If you know only two things about shotguns—they go bang! and kick like a mule—you are only doing it half right. And, I am sorry to say, you know what it feels like to be kicked by a mule, but that is a story for another day. Not only does a shotgun NOT have to recoil like sledgehammer—it should not with the right ammunition and accessories.

Winchester AA TrAAcker 12 gauge shotgun ammo box

Winchester’s AA TrAAcker 12 gauge shotgun ammo. Note the 2 3/4 Dr. Eq.

Modern shotgun technology has incorporated several independent systems to reduce recoil; springs, dampeners, gels and rubber components are regularly used, sometimes in conjunction, to reduce recoil. Of course, the shotgun shell itself has a lot to do with felt recoil. The “secret” to determining the expected recoil and stopping power is printed right on the box.

If you’re lucky, occasionally you’ll stumble upon a box of shotshells that’s labeled “Low Recoil.” But most aren’t, which leads us to the one thing that’s still printed on nearly every box of modern shotshells produced today: Dram Equivalent.

The term “dram equivalent” is a holdover from the days when shotshells were loaded with black powder. Black powder is (or at least was) measured in “drams.” This is a weight measure, where 16 drams equal one ounce. At that measurement, 256 drams of black powder weighed one pound. (Trivia bonus! A pound of black powder is actually known as an “avoirdupois pound.”) All of that’s fine and good if you’re shooting a black powder shotgun—and that’s not likely. The shotshells you find on your retailer’s shelves today are, of course, loaded with modern smokeless propellants. These gunpowders are much lighter than black powder in the same volume, thus, loading a shell with smokeless powder using a black powder weight chart would be akin to shoving a small stick of dynamite in the barrel.

youth wearing orange safety vest and shotgun

Picking the right load for the shooter and need (target versus hunting or home defense) often dictates the difference between success and someone who will resist continuing in the sport.

What we end up with then is the term “dram equivalent.” The one word in that term that deserves the focus is “equivalent.” Paired with “dram,” this became a way for manufacturers to communicate to shotgunners the power of the charge in the shell. This gives the shooters an idea of how the shell performs—the amount of pressure generated by the smokeless powder compared to the black powder for which those first smokeless powder users had so long been accustomed. Those early smokeless shooters understood what 3½ drams of black powder in their shotgun felt like in terms of recoil and performed in terms of knockdown power. While there are few shotgunners today who know what shooting black powder shotshells really feels like, the rating system on boxes of shotshells stuck and is still used today.

The main takeaway you need to remember is the larger the dram equivalent, the larger the powder charge and more force the shell will produce.

For instance, most clay target sports mandate that shotshells be no more than “3 Drams Equivalent” in order to keep noise and the distance shot will travel minimized on public ranges. Clay target shooters also don’t want a heavy recoiling load, because such heavy loads will fatigue a shooter over a long day’s competition of 100 to 200 rounds or more. Many hunting loads carry dram equivalent markings quite a bit higher than that. Regardless, when you’re armed with the knowledge of what dram equivalents really are, you are better prepared to select the ammunition best suited for your intended shotgunning needs.

Have you ever considered the dram equivalent when purchasing shotshells? Know of another term that would be helpful to new or experienced shooters? Share them with us in the comment section.

This article was originally published in the National Shooting Sports Foundation First Shots Newsletter.

SLRule

Growing up in Pennsylvania’s game-rich Allegany region, Dave Dolbee was introduced to whitetail hunting at a young age. At age 19 he bought his first bow while serving in the U.S. Navy, and began bowhunting after returning from Operation Desert Shield/Desert Storm. Dave was a sponsored Pro Staff Shooter for several top archery companies during the 1990s and an Olympic hopeful holding up to 16 archery records at one point. During Dave’s writing career, he has written for several smaller publications as well as many major content providers such as Guns & Ammo, Shooting Times, Outdoor Life, Petersen’s Hunting, Rifle Shooter, Petersen’s Bowhunting, Bowhunter, Game & Fish magazines, Handguns, F.O.P Fraternal Order of Police, Archery Business, SHOT Business, OutdoorRoadmap.com, TheGearExpert.com and others. Dave is currently a staff writer for Cheaper Than Dirt!

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Comments (27)

  • Jim in Houston

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    Aside from dram equivalent and velocity, the other things people have suggested like the type of propellant are not really knowable by the consumer, so tenet don’t have much vague if you are in the store looking at a shelf of spot shells and trying to pick out a lower recoil load.As to the height of the brass case, you can have high our low recoil slugs or buckshot, both with the high brass case.

    Reply

  • Mike

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    Another thing that affects perceived recoil is the burn rate of the powder. Magnum shotshells generally use a slower burning powder which gives more of a hard push. The lighter loads use faster burning powder which gives a sharper, although lighter, kick. Now if I could just tame down a
    2 oz heavyshot blend turkey load.

    Reply

  • RALPH CARTER

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    Re Dave Dolbee’s article on shotgun powder loads:

    Dave refers to recoil control techniques and devices and lists “dampeners”. I find it hard to understand how one can dampen (moisten or wet) to control recoil. Perhaps submerge the gun in water? I think the meaningful term would be “damp or dampers” (to suppress motion or intensity). Just a thought.

    Reply

  • Neal

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    I still load black powder shotshells with both lead and steel shot. My 10 gauge duck and goose load carries 5 drams of powder and is impressive on the shoulder…great fun.

    Reply

  • Kirk

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    Another way to help get a general idea is if the shell is “hi brass” or “low brass”. The brass base on shotshells is not always the same. Lower power loads like those used for clay birds or some bird hunting is low brass, meaning the brass base is shorter. On heavier loads like buckshot, slug, or even some other types of hunting loads intended for things like geese that require a longer range have a taller base, allowing for a heavier powder charge. This is not divulged on the box, but popping open the top and taking a quick peek will reveal this. After you have seen the difference, it is obvious to a quick look.

    Reply

  • Richard

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    Another “Aha!” post. Thanks for the info and keep them coming.

    Reply

  • Jim in Houston

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    In the absence of dram equivalent ratings, I look at the velocity of the shot, which generally does appear on the box. Without getting into the finer points of physics that Leon pointed out, a velocity of 1185 or 1250 is low recoil, above 1300 and you get into the heavier stuff. Compare the velocities for the type of shot you shoot. The lower velocities for the same shot are the low recoil loads.

    Reply

    • Tommy in Tahuya

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      As a shotgun shooting instructor, I agree with Jim’s summary on looking at stated velocities. And, the higher the weight of the shot loaded produces more felt recoil.

      Reply

  • rk campbell

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    Excellent. I am primarily a handgunner and really appreciate this feature. Added to my education.

    bob

    Reply

  • Leon

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    Robert,
    Other than contacting the manufacturer of your shotshells and asking what powder they use, if they’ll even tell you, no idea on that. On the other aspect of what info can help shooters estimate how much kick they’ll get in the shooting shoulder, I think of the physics involved. Without getting into the actual math, which is messy unless you have at least a Masters degree, just look at the weight of the payload and how fast it says on the box that the payload leaves the muzzle. Common example, a 12-guage 1oz. shotgun deer slug, in 2-3/4″ shell, in the famous green and yellow box, says it goes 1560 feet per second. That same weight slug in a 3″ shell, hence more room for powder behind it, with the big red W on the box, (darn, shot those all up) goes around 1700 fps, if I recall correctly. It takes more energy to move that same weight faster, given the same barrel length which gives almost the same powder burn time (shorter barrel=slightly slower velocity and more holdover required for same downrange target distance). Now, I also just compared two different companies’ products, so some of the added room in the 3″ might be occupied by a different wad design also, some of which are designed to try to soak up a tiny bit of the initial jolt when the powder first ignites … or it could be a hotter-burning powder formula … just sayin’ from my experience trying to zero scopes on my deer shotguns, before acquiring a rifle and having my area opened up to rifles by the state conservation folks.

    Reply

  • Robert

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    I have always wondered about why the dram weight was on shot shells. Thanks for informing me! Another question, if anyone can answer it for me is: is there any way to know what type of proellant( powder) is loaded into those shells? I hand load, and am having trouble finding pistol powder. I could preorder some, but I have found that shotgun shell powder and pistol powder are used for both. Meaning, could I , say, but a box of # 4 or buck shot, and use the powder from just that box, of course starting with a low charge, and work it up slowly? I also have quite a few . 38 special, .357 mag., and 44 mag cartridges that I have not yet “recycled” for the powder. I know it isn’t something that most would endorse to do as a regular process, but I am trying to get started on .357 Sig loads for both 124 and 147 gr bullets. Any opinions will be greatly appreciated. Thanks

    Reply

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