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

W3645 AFF 8419+
W3645 AFF 8419+

The Armed Citizen® Aug. 7, 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.

Gun of the Week: Zev Technologies x Magpul FDP-C

One of the most anticipated firearm releases of 2026 was the Zev Technologies FDP, a folding pistol-caliber design that the company produced in conjunction with Magpul Industries.

Review: Taurus 22TUC

Taurus USA's 22TUC is a little, polymer-framed .22 pocket pistol with a tip-up barrel design that, unlike many of the company's guns, is made entirely in the United States.

Korea Coast Guard Increases KelTec KSG Tactical Shotgun Inventory

KelTec recently announced that the Korea Coast Guard has ordered more KSG shotguns to join those already in service aboard the branch's patrol vessel fleet.

Rifleman Review: Mossberg 990 Aftershock

In 2025, Mossberg added to the non-NFA, shotshell-firing firearm category with its 990 Aftershock, which uses a semi-automatic operating mechanism while still maintaining a compact form factor.

Next-Gen Micro Red-Dot: The Steiner MPS 2.0

Steiner Optics has introduced the next-generation version of its Micro Pistol Sight, a red-dot optic that first hit the market in 2021.

Interests



Get the best of American Rifleman delivered to your inbox.