Rifleman Q&A: Bullet & Primer Sealant

by
posted on September 19, 2021
** When you buy products through the links on our site, we may earn a commission that supports NRA's mission to protect, preserve and defend the Second Amendment. **
Qamain

Q. I recently purchased some pulled, military surplus bullets. They have quite a bit of black residue on them that I assume was the water sealant between the bullet and inside the case mouth. What is the sealant material made of?


A. The sealant used by ammunition manufacturers on bullets is usually an asphalt-based chemical. Very few handloaders think it to be necessary, and I personally don’t know of any who do try to duplicate the factory waterproofing. Handloads are typically used within a few years, and in that time, with the handloads stored in reasonably uniform conditions, there is very little possibility of moisture penetrating the physical seal between bullet and case mouth. The same goes for primer sealers. These two seals are primarily used on military ammunition, where storage and time considerations are more important.

—Dave Andrews


This “Questions & Answers” was featured in the October 2004 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 Treakle.

To subscribe to the magazine, visit NRA membership page here and select American Rifleman as your member magazine.

Latest

150 Year Old 1
150 Year Old 1

Nation's Oldest Gun Club Turns 150

The oldest continuously operating rifle club in the United States, the Newport Rifle Club (NRC) near Middletown, R.I., is celebrating its 150th anniversary in 2026.

Preview: Antimatter Industries Scopeswitch 2.0

This new made-in-USA riflescope mount from Antimatter Industries changes how shooters engage targets.

Tension Destroys Your Shooting Performance. Here's How to Manage It.

Whether you’re managing a lethal-force encounter, running a stage in competition or working a timed drill from concealment, performance shooting reigns king, and one of the most brutal and insidious king-slayers of all time is self-induced tension.

EchoCore Suppressors: Embracing The Silence Using Innovative Design

It’s difficult, especially for a brand-new manufacturer, to stand out in a very crowded space, but EchoCore Suppressors has accomplished just that and notched some prestigious accolades along the way.

Gun of the Week: Dark Mountain Arms Stowaway

The Dark Mountain Arms Stowaway rifle is a bolt-action, single-shot design chambered for the 5.7x28 mm FN cartridge.

The Armed Citizen® Feb. 27, 2026

Read today's "The Armed Citizen" entry for real stories of law-abiding citizens, past and present, who used their firearms to save lives.

Interests



Get the best of American Rifleman delivered to your inbox.