Back in the old days, shooters didn’t load shotshells with clean-burning, smokeless propellant. We loaded them with black powder, which we measured in a unit called dram.

What is Dram Equal To?

As a unit of weight measurement, one dram is equal to 27.344 grains or 0.0625 ounces. There are 16 drams to an ounce.

Origins: Modern Powders vs. Black Powder

12 gauge shell with powder spilling out to show dram charge

Modern propellant is far more potent than black powder. If you loaded 3.5 drams of modern propellant in a standard shotshell, you would probably wind up blowing your shotgun to smithereens. This is why ammo manufacturers don’t tell you how many drams of modern propellant they loaded in a shotshell. As far as they are concerned, it is an obsolete measurement.

When the switch to modern propellant occurred, it created a problem. Shooters who were accustomed to judging a shotshell’s power based on the amount of black powder it held still wanted that valuable information. Thus the “dram equivalent” was invented. It told those folks how powerful a shotshell would be if it were loaded with black powder instead of an analogous charge modern propellant.

Aside from historic firearm enthusiasts, very few people nowadays will ever experience firing a black powder shotshell. The practice of including a shotshell’s dram equivalent on its packaging has persisted, however, as it still provides useful information.

How Dram Works

Shooting a 12 gauge shotgun

Suppose you have two 12 Gauge shotshells, each with 1-1/8 ounces of shot. One has a dram equivalent of three; the other, four. The shell with the higher dram equivalent will have a load velocity of 1,420 feet per second, whereas the shell with the lower dram equivalent will have a load velocity of only 1,200 fps. You can also reasonably expect the shell with the higher equivalent to produce greater recoil energy and a louder report.

How Can Modern Shooters It?

Because a shell’s dram equivalent reflects both its muzzle velocity and its report, it is useful for target shooting ranges that want to restrict how powerful their guests’ ammunition can be. (Perhaps they want to limit noise or prevent shot pellets from traveling too far.) Simply banning shells with muzzle velocities faster than X or shot columns heavier or lighter than Y wouldn’t take enough variables into account. A dram equivalent, on the other hand, provides a comprehensive measure of just how powerful a shell really is.

You might also refer to a shell’s equivalent if you want to break in a semi-automatic shotgun correctly, or avoid ammo that produces a lot of recoil while you are target shooting or upland game hunting. Many ammo manufacturers omit their shotshells’ dram equivalents from their packaging these days, but determining a 12 Gauge shell’s equivalent is easy enough. Just consult the chart below.

12 Gauge Dram Equivalent Chart

Shot Weight (oz)5/83/47/811-1/81-1/41-3/81-1/21-5/81-3/41-7/822-1/82-1/4