CCI Large Pistol Primers #300 Box of 1000

Last reviewed: 2026-04-17 by Jake Terry, FFL07/SOT3, NRA-certified firearms instructor.

CCI large pistol primers form the ignition foundation for centerfire handgun cartridges from .45 ACP through .44 Magnum. The #300 designation identifies CCI’s standard large pistol primer—a non-corrosive, non-mercuric Boxer primer measuring 0.210 inches in diameter and engineered to fit large-pistol primer pockets in brass cases. Handloaders select these primers when assembling practice ammunition, defensive loads, and hunting cartridges that require reliable ignition without magnum-strength anvil stiffness. CCI manufactures every primer at its Lewiston, Idaho facility, where automated priming compound distribution and four-point anvil inspection maintain lot-to-lot consistency that competitive shooters and volume reloaders depend on for single-digit extreme-spread velocities.

Performance at a Glance

Each CCI #300 primer seats with 0.002–0.004 inch crush when pressed to specification depth, creating the preload necessary for consistent anvil contact during firing-pin strike. The priming compound ignites at approximately 4 pounds of firing-pin energy—sufficient for double-action revolvers and striker-fired pistols alike—while remaining insensitive to inertial setback during chambering in floating firing-pin designs. CCI engineers the compound to function across ambient temperatures from –20°F to +125°F without ignition-delay variation, a specification validated in accelerated environmental testing that simulates vehicle storage in summer heat and winter cold.

Handloaders chamber the #300 in .45 ACP, 10mm Auto, .44 Special, .44 Magnum (with appropriate powder charges), .45 Colt, and similar large-pistol cartridges. The standard anvil stiffness pairs with ball powders like Accurate #5 and flake powders like Titegroup without requiring magnum primers, though magnum loads in .44 Magnum and .454 Casull benefit from CCI’s #350 magnum large pistol primer when powder charges exceed 20 grains of slow-burning propellant. Browse the full large pistol primers selection for magnum and small-pistol alternatives.

Who It’s For

Volume handloaders assembling 500+ rounds per session rely on the #300’s consistency to minimize charge-weight adjustments across lot changes. Competitive pistol shooters—USPSA, IDPA, Bullseye—select these primers when building .45 ACP match ammunition that requires sub-20 fps extreme spread at 25 yards. Cowboy Action shooters running black-powder substitute loads in .45 Colt appreciate the non-corrosive formulation that permits extended cleaning intervals between range sessions. Defensive handloaders assembling carry ammunition in 10mm Auto or .45 ACP pair the #300 with jacketed hollow points and powders like Longshot or Power Pistol to achieve published velocity targets without pressure signs.

Reloading Notes

Seat primers to 0.002–0.004 inch below flush using a hand priming tool or progressive press with adjustable seating depth. Over-seating crushes the anvil and increases slam-fire risk; under-seating leaves the primer proud and may prevent full chambering or cause misfires due to insufficient crush. Store primers in original plastic trays inside the factory box, away from solvents, oils, and moisture that degrade priming compound sensitivity. CCI ships primers in 1000-count boxes packed in ten 100-count trays; some shipments arrive in white OEM packaging rather than retail boxes, with identical primer specification and performance. Hazmat shipping fees apply to all primer orders due to UN0044 classification as a Division 1.4S explosive.