Rimfire ammo terminology: standard, high velocity, subsonic, match, plated and more

Written in our own words from the sources cited after each fact. We haven't run hands-on tests for this page; where sources disagree we say so. Prefer the primary source (SAAMI, the maker, the governing body) if anything here conflicts with it.

Subsonic: Slower than the speed of sound. CCI uses 1,125 fps as the line^[CCI]; the real value shifts with temperature and altitude.
Standard velocity: Usually subsonic or close to it. CCI Standard Velocity runs 1,070 fps^{[CCI (Standard Velocity 1,070 fps)]}.
High velocity: Supersonic hunting and plinking loads. CCI Mini-Mag is listed at 1,260 fps^{[CCI 2026 catalog]}.
Hyper velocity: Lighter bullets pushed faster. CCI Stinger: 32 gr at 1,640 fps^{[CCI Stinger (32 gr, 1,640 fps)]}. Wikipedia notes the Stinger case is slightly longer than standard .22 LR^[Wikipedia].
Quiet / CB: Very low-powered loads. CCI Quiet-22 runs 710 fps^{[CCI 2026 catalog]}, and CCI CB Long uses a 29 gr bullet at 710 fps^{[CCI CB Long (29 gr, 710 fps)]}. These may not cycle semi-autos.
Match / target: Loads made for consistency rather than speed; SAAMI's table includes a match rifle .22 LR load^{[ANSI/SAAMI Z299.1-2026 (rimfire)]}.
Lead vs plated: Plain lead bullets are lubricated; plated bullets have a thin copper wash. Stinger is copper-plated^{[CCI Stinger (32 gr, 1,640 fps)]}.
Heeled bullet: A bullet the same diameter as the case with a reduced heel inside it, as on .22 LR^[Wikipedia]. The .21 Sharp avoids this^{[American Rifleman]}.
MAP: Maximum Average Pressure, SAAMI's recommended maximum for commercial loads; 24,000 psi for .22 LR^{[ANSI/SAAMI Z299.1-2026 (rimfire)]}.

Deeper: subsonic vs standard vs high velocity · drop and wind charts.

Rimfire ammo terminology: standard, high velocity, subsonic, match, plated and more

Sources

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