Rifleman Q&A: Dram Equivalent

Q. Looking at the variety of shotgun ammunition available at my local gun shop, I have noticed that some boxes list “dram equivalent” along with shot size and shell length. Can you explain the term’s significance? Do more drams mean better performance?

A. More and more ammunition manufacturers are printing the actual velocity of various shotshell loads on the boxes. Still, though, many continue to print dram-equivalent data on ammunition boxes. When all shotshells were loaded with blackpowder, all were loaded with specific charges measured in drams. When smokeless powder first came on the scene, these powders were called “bulk” powders, since they were loaded bulk-for-bulk the same as blackpowder, which resulted in comparable velocities. Therefore, printing the dram equivalent on a box of smokeless-powder shotshells gave the buyer guidance as to its performance.

Nowadays, the actual velocity tells us much more. The accompanying table compares common dram-equivalents with actual velocities for all common gauges.

—John M. Taylor, Contributing Editor

This “Questions & Answers” was featured in the November 2005 issue of American Rifleman. At time of publication, "Questions & Answers" was compiled by Staff, Ballistics Editor William C. Davis, Jr., and Contributing Editors: David Andrews, Hugh C. Birnbaum, Bruce N. Canfield, O. Reid Coffield, Charles Q. Cutshaw, Charles M. Fagg, Angus Laidlaw, Evan P. Marshall, Charles E. Petty, Robert B. Pomeranz, O.D., Jon R. Sundra, Jim Supica, A.W.F. Taylerson, John M. Taylor and John W. Treakle.

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