CaliberAtlas › Guides › 5.56 Commercial: a separate SAAMI standard
5.56 Commercial (5.56 COMM) has its own commercial standard. This page explains the distinction from 5.56 NATO and .223 Remington.
By Preston Willis · Published October 28, 2026 · Last updated October 28, 2026
SAAMI announced acceptance on October 12, 2026. Introduced by Hornady, 5.56 Commercial provides a public commercial cartridge-and-chamber standard using SAAMI Z299.4 procedures. The designation is voluntary; manufacturers need not adopt it in firearm markings or ammunition headstamps.
Meeting this commercial specification does not establish compliance with military or NATO specifications. SAAMI says blanket compatibility statements are not possible. Ask the firearm or ammunition manufacturer about a specific combination carrying different markings.
A firearm chambered and marked only .223 Remington must use only .223 Remington ammunition. SAAMI identifies using any 5.56 ammunition, including 5.56 Commercial, in a .223 Remington chamber as unsafe.
This is standards coverage, not a new ballistic catalog record or a compatibility checker. Existing NATO and .223 records remain separate. Current retail availability under the 5.56 Commercial name has not been verified.
SAAMI acceptance announcement — October 12, 2026
Source checked .
Separate catalog pages: 5.56×45mm NATO and .223 Remington.