The .222 Remington features a maximum case length of 1.700 inches (43.18 mm), a rim diameter of 0.378 inches (9.60 mm), a rim thickness of 0.045 inches (1.14 mm), a base diameter of 0.376 inches (9.55 mm), a shoulder diameter of 0.357 inches (9.07 mm), a neck diameter of 0.253 inches (6.43 mm), a neck length of approximately 0.313 inches (7.95 mm), and a maximum overall cartridge length of 2.130 inches (54.10 mm). Published numerical specifications represent nominal engineering targets, maximum manufacturing boundaries, or MIN/MAX tolerance windows depending on whether SAAMI or C.I.P. standards are cited. SAAMI regulates voluntary specifications in North America, while C.I.P. enforces mandatory proof standards across Europe. Internal case capacity and actual physical measurements show subtle variations across manufacturers such as Remington, Winchester, Lapua, Nosler, and Norma. Understanding these standardized measurements ensures proper headspacing, reliable extraction, precise reloading die setup, and safe operating pressures.
222 Remington Case Dimensions
| Case Dimension | Inches | Millimeters | Specification Type | Source | Notes |
| Case Length | 1.700 in | 43.18 mm | Maximum | SAAMI Standard | Tolerance: -0.020 in (-0.51 mm) |
| Rim Diameter | 0.378 in | 9.60 mm | Maximum | SAAMI Standard | Tolerance: -0.010 in (-0.25 mm) |
| Rim Thickness | 0.045 in | 1.14 mm | Maximum | SAAMI Standard | Tolerance: -0.010 in (-0.25 mm) |
| Base Diameter | 0.376 in | 9.55 mm | Maximum | SAAMI Standard | Tolerance: -0.008 in (-0.20 mm) |
| Shoulder Diameter | 0.357 in | 9.07 mm | Maximum | SAAMI Standard | Body wall tapers to body-shoulder junction |
| Neck Diameter | 0.253 in | 6.43 mm | Maximum | SAAMI Standard | Measured with bullet seated |
| Neck Length | 0.313 in | 7.95 mm | Nominal Reference | C.I.P. / Reference | Distance from neck-shoulder junction to mouth |
| Shoulder Angle | 23.0 degrees | 23.0 degrees | Nominal | SAAMI Standard | 46 degrees included angle |
| Overall Cartridge Length | 2.130 in | 54.10 mm | Maximum | SAAMI Standard | Nominal testing length is 2.130 in (54.10 mm) |
| Case Capacity | 27.0 gr H2O | 1.75 cm³ | Nominal Average | Hornady / Lapua | Varies by brand (26.5 to 28.0 gr H2O) |
| Maximum Pressure | 50,000 PSI | 3,700 bar | Maximum Allowable | SAAMI MAP | C.I.P. Pmax is set at 3,700 bar (53,664 PSI) |
Understanding The 222 Remington Case Dimensions
Evaluating the .222 Remington technical profile requires understanding how each structural measurement operates within a firearm chamber:
- Case Length: The total distance from the exterior face of the case head to the mouth. Proper case length prevents the mouth from wedging into the chamber throat, preventing severe pressure spikes.
- Rim Diameter: The outer boundary of the rim face. It establishes the extractor slot dimensions and defines the small-bolt face standard (0.378 in) shared by several rimless cartridge families.
- Rim Thickness: The vertical depth of the rim wall. It controls extractor engagement and bolt face clearance.
- Base Diameter: The exterior body width located forward of the extractor groove. It governs fit within the rear portion of the chamber.
- Shoulder Diameter: The case width where the body taper transitions into the shoulder angle.
- Neck Diameter: The outer neck measurement with a seated projectile. Proper clearance between the outer neck and chamber neck allows clean release of the bullet upon firing.
- Neck Length: The length of straight cylindrical brass gripping the projectile. A long neck length ensures proper alignment and bullet retention.
- Shoulder Geometry: Consists of a gradual body taper ending in a 23 degree shoulder angle, which forms the primary contact surface for setting chamber headspace.
- Overall Cartridge Length: The base-to-tip length of an assembled round. This guarantees fit in standard mini or short-action magazine boxes.
- Case Capacity: The volume of water held by an unprimed, fired case filled flush to the mouth. Volume directly influences peak pressure and velocity potential for given powder charges.
222 Remington Case Dimensions In Inches And Millimeters
The following reference table converts primary SAAMI and C.I.P. .222 Remington dimensions into imperial and metric units.
| Dimension Description | Inches (Imperial) | Millimeters (Metric) | Type / Definition |
| Maximum Case Length | 1.700 in | 43.18 mm | Upper limit for raw brass length |
| Minimum Case Length | 1.680 in | 42.67 mm | Lower SAAMI manufacturing limit |
| Trim-To Case Length | 1.690 in | 42.93 mm | Recommended handload prep target |
| Maximum Rim Diameter | 0.378 in | 9.60 mm | Upper boundary for bolt face fit |
| Minimum Rim Diameter | 0.368 in | 9.35 mm | Lower boundary for rim machining |
| Maximum Base Diameter | 0.376 in | 9.55 mm | Max expansion zone near case head |
| Maximum Shoulder Diameter | 0.357 in | 9.07 mm | Junction point where body meets shoulder |
| Maximum Neck Diameter | 0.253 in | 6.43 mm | Exterior neck with loaded projectile |
| Bullet Diameter | 0.224 in | 5.69 mm | Standard projectile outside diameter |
| Maximum Overall Length (COAL) | 2.130 in | 54.10 mm | Maximum length for magazine clearance |
222 Remington Case Length
The published maximum case length for the .222 Remington is 1.700 inches (43.18 mm) under SAAMI standards, while C.I.P. documentation lists maximum case length as 43.18 mm. The recommended trim-to length for handloaders is 1.690 inches (42.93 mm), establishing a 0.010 inch safety margin below the absolute maximum.
During the firing cycle, internal pressures push brass to flow forward toward the neck. If a case stretches beyond the 1.700 inch maximum limit, the case mouth can pinch against the chamber neck shoulder, pinching the bullet and causing dangerous chamber pressure spikes. Regular trimming ensures smooth extraction and consistent neck tension.
222 Remington Base And Rim Dimensions
The .222 Remington features a rimless case design with a maximum rim diameter of 0.378 inches (9.60 mm) and a maximum base diameter of 0.376 inches (9.55 mm). Rim thickness measures a maximum of 0.045 inches (1.14 mm).
The 0.378 inch rim diameter created a benchmark for light-recoil, high-precision cartridges. Because the base diameter directly forward of the extractor groove measures 0.376 inches, the rim sits virtually flush with the case body. This true rimless profile ensures reliable feeding from bolt-action and semi-automatic internal magazines, with headspacing established off the 23 degree shoulder rather than the rim face.
222 Remington Shoulder And Neck Dimensions
The shoulder and neck geometry of the .222 Remington is celebrated for its inherently accurate design:
- Shoulder Diameter: 0.357 inches (9.07 mm) maximum at the body-shoulder junction.
- Shoulder Angle: 23.0 degrees (46.0 degrees included angle).
- Neck Diameter: 0.253 inches (6.43 mm) maximum with a seated bullet.
- Neck Length: Approximately 0.313 inches (7.95 mm).
The prominent 0.313 inch long neck is a hallmark feature of the .222 Remington (often called the “Triple Two”). This unusually long neck provides ample bearing surface to hold .224 caliber bullets perfectly straight and aligned with the bore centerline, contributing significantly to the legendary benchrest accuracy of the cartridge.
222 Remington Case Capacity
Published and measured water capacity for .222 Remington brass typically spans between 26.5 grains H2O and 28.0 grains H2O (1.72 cm³ to 1.82 cm³) when measured level with the case mouth on a fired case, averaging roughly 27.0 grains H2O.
Internal capacity varies across different ammunition manufacturers:
- Remington / Winchester Brass: Features moderate wall thickness, yielding internal capacities near 27.0 to 27.5 grains H2O.
- Hornady / Nosler Brass: Averages approximately 26.8 to 27.2 grains H2O.
- Lapua / Norma Brass: Demonstrates thicker case construction, resulting in slightly lower internal volume closer to 26.5 to 26.8 grains H2O.
Because small volume changes alter peak combustion pressures in compact cases, load data developed in lighter, higher-capacity brass should not be applied directly to heavier, lower-capacity brass without stepping down powder charges.
222 Remington Bullet Diameter
The standardized bullet diameter for the .222 Remington is 0.224 inches (5.69 mm). SAAMI bullet tolerances range between 0.221 inches and 0.224 inches.
It is vital to distinguish bullet diameter from barrel dimensions:
- Bullet Diameter: 0.224 inches (5.69 mm).
- Bore Diameter (Land to Land): 0.219 inches (5.56 mm).
- Groove Diameter (Groove to Groove): 0.224 inches (5.69 mm).
Common .224 caliber commercial projectiles used in the .222 Remington weigh between 40 grains and 55 grains. Traditional 1:14 inch barrel twist rates in factory rifles favor lighter 45 to 52 grain bullets to achieve benchrest-grade stability and accuracy.
222 Remington Overall Cartridge Length
SAAMI specifies a maximum overall cartridge length (COAL) of 2.130 inches (54.10 mm) for the .222 Remington, while specifying a minimum testing length of 2.080 inches (52.83 mm).
The 2.130 inch limit allows the .222 Remington to fit comfortably inside micro and short-action magazine boxes. Factory target and varmint ammunition generally measures between 2.100 inches and 2.130 inches. When handloading, seating depth can be fine-tuned relative to the rifling lands to maximize accuracy while retaining reliable magazine feed.
222 Remington Dimensions vs Similar Cartridges
Comparing the .222 Remington against structurally similar .22 caliber cartridges illustrates its size, geometry, and internal volume.
| Cartridge | Bullet Diameter | Case Length | Overall Length | Rim / Base Diameter | Case Capacity | Source |
| .222 Remington | 0.224 in (5.69 mm) | 1.700 in (43.18 mm) | 2.130 in (54.10 mm) | 0.378 in / 0.376 in | ~27.0 gr H2O | SAAMI |
| .223 Remington | 0.224 in (5.69 mm) | 1.760 in (44.70 mm) | 2.260 in (57.40 mm) | 0.378 in / 0.376 in | ~31.4 gr H2O | SAAMI |
| .222 Remington Magnum | 0.224 in (5.69 mm) | 1.850 in (46.99 mm) | 2.280 in (57.91 mm) | 0.378 in / 0.376 in | ~34.0 gr H2O | SAAMI |
| .221 Remington Fireball | 0.224 in (5.69 mm) | 1.400 in (35.56 mm) | 1.830 in (46.48 mm) | 0.378 in / 0.376 in | ~22.5 gr H2O | SAAMI |
| .204 Ruger | 0.204 in (5.18 mm) | 1.850 in (46.99 mm) | 2.260 in (57.40 mm) | 0.378 in / 0.376 in | ~32.5 gr H2O | SAAMI |
| 5.56x45mm NATO | 0.224 in (5.69 mm) | 1.760 in (44.70 mm) | 2.260 in (57.40 mm) | 0.378 in / 0.376 in | ~31.5 gr H2O | MIL-SPEC |
Dimensional similarities do not indicate interchangeable ammunition. Each cartridge requires its specific dedicated chamber.
222 Remington vs 223 Remington Case Dimensions
The .222 Remington is the direct parent of the .223 Remington, but the two cartridges differ in length, neck design, and capacity:
- Case Length: The .222 Remington has a shorter case length of 1.700 inches (43.18 mm) compared to 1.760 inches (44.70 mm) for the .223 Remington.
- Neck Length: The .222 Remington features a noticeably longer neck (0.313 in) relative to its body length than the .223 Remington (0.203 in), giving it an advantage in bullet concentricity.
- Case Capacity: The .223 Remington holds approximately 31.4 grains H2O compared to 27.0 grains H2O in the .222 Remington, granting the .223 roughly 100 to 150 ft/s more velocity.
- Overall Length: Maximum COAL for the .222 Remington is 2.130 inches, whereas the .223 Remington extends to 2.260 inches.
222 Remington vs 222 Remington Magnum Case Dimensions
Introduced in 1958, the .222 Remington Magnum was designed as an elongated offshoot of the original .222:
- Case Length: The Magnum version lengthens the case body to 1.850 inches (46.99 mm), 0.150 inches longer than the 1.700 inch .222 Remington.
- Base and Rim: Both share identical rim (0.378 in) and base (0.376 in) diameters.
- Case Capacity: The longer body increases capacity from ~27.0 grains H2O up to ~34.0 grains H2O.
- Overall Length: COAL increases from 2.130 inches (.222 Rem) to 2.280 inches (.222 Rem Mag).
222 Remington vs 221 Remington Fireball Case Dimensions
The .221 Fireball was created by shortening the .222 Remington case for use in handguns like the Remington XP-100:
- Case Length: The .221 Fireball reduces the case length down to 1.400 inches (35.56 mm), compared to the .222’s 1.700 inches.
- Base and Rim Profile: Both cartridges share the same 0.378 inch rim and 0.376 inch base diameters.
- Case Capacity: The shortened body holds ~22.5 grains H2O versus the .222’s ~27.0 grains H2O.
- Overall Length: The Fireball uses a compact maximum COAL of 1.830 inches compared to 2.130 inches.
222 Remington Chamber And Case Dimensions
Chamber geometry is engineered slightly larger than maximum cartridge dimensions to ensure smooth feeding and extraction in production rifles.
SAAMI chamber specifications establish these spatial relationships:
- Headspace Control: Headspace is measured from the bolt face to a 0.350 inch datum line on the 23 degree shoulder.
- Chamber Neck: The chamber neck diameter is cut to a minimum of 0.257 inches, providing approximately 0.004 inches of total neck clearance around a maximum 0.253 inch loaded case neck.
- Chamber Length: Chamber length is cut slightly beyond the maximum 1.700 inch brass boundary (typically 1.710 inches minimum) to avoid pinching the mouth during firing.
- Body Clearance: Chamber walls feature roughly 0.002 to 0.003 inches of clearance over maximum case body dimensions to ensure easy extraction.
222 Remington Case Forming And Resizing
Designed from scratch by Mike Walker at Remington in 1950, the .222 Remington was an entirely new cartridge rather than a necked-down modification of an existing parent case. Its balanced design served as the foundation for the entire .223/5.56mm family.
Understanding these dimensional mechanics helps handloaders set up resizing equipment properly. Full-length sizing dies should be set to bump the shoulder back slightly (typically 0.001 to 0.002 inches) for bolt-action rifles to maintain correct headspacing without over-working the brass, ensuring long case life and preserving the benchrest precision the round is famous for.
222 Remington Manufacturer Specifications vs Actual Measurements
Differences often appear when comparing official standard drawings, commercial factory ammunition, and fired brass measurements:
- SAAMI Standards: Define voluntary maximum cartridge and minimum chamber limits for North American manufacturers. Drawings represent safety ceilings rather than exact factory ammunition dimensions.
- C.I.P. Specifications: Establish mandatory legal limits across European proof houses. C.I.P. lists maximum case length at 43.18 mm and sets maximum allowable pressure (Pmax) at 3,700 bar.
- Factory Ammunition: Loaded factory rounds from Remington, Federal, or Norma are manufactured slightly below maximum SAAMI limits (often 0.002 to 0.004 inches smaller) to ensure effortless chambering.
- Fired Cases: Upon ignition, thin brass expands to fill the chamber, causing fired dimensions to reflect the individual rifle’s chamber size.
- Resized Cases: Processing brass through sizing dies restores dimensions back toward SAAMI minimums, with minor variations caused by metal elasticity.
Official specification drawings from SAAMI and C.I.P. remain the authoritative baseline for primary case measurements.
Common Questions
What are the 222 Remington case dimensions?
Key maximum specifications under SAAMI drawings include a case length of 1.700 in (43.18 mm), rim diameter of 0.378 in (9.60 mm), rim thickness of 0.045 in (1.14 mm), base diameter of 0.376 in (9.55 mm), shoulder diameter of 0.357 in (9.07 mm), neck diameter of 0.253 in (6.43 mm), shoulder angle of 23 degrees, and COAL of 2.130 in (54.10 mm).
What is the 222 Remington case length?
The maximum SAAMI case length is 1.700 inches (43.18 mm), with a minimum manufacturing limit of 1.680 inches (42.67 mm). The standard trim-to length for handloading is 1.690 inches (42.93 mm).
What is the 222 Remington rim diameter?
The maximum rim diameter is 0.378 inches (9.60 mm) with a manufacturing tolerance of -0.010 inches (-0.25 mm).
What is the 222 Remington base diameter?
The maximum base diameter measured forward of the extractor groove is 0.376 inches (9.55 mm).
What is the 222 Remington shoulder diameter?
The maximum shoulder diameter at the body-shoulder junction is 0.357 inches (9.07 mm).
What is the 222 Remington neck diameter?
The maximum neck diameter of a loaded round with a bullet seated is 0.253 inches (6.43 mm).
What is the 222 Remington case capacity?
Nominal water capacity averages 27.0 grains H2O (1.75 cm³), spanning from 26.5 to 28.0 grains H2O depending on brass brand wall thickness.
What is the 222 Remington overall cartridge length?
Maximum overall cartridge length (COAL) is 2.130 inches (54.10 mm) to fit standard mini and short-action magazine boxes.
How does 222 Remington compare with 223 Remington case dimensions?
The .222 Remington has a shorter case length (1.700 in vs 1.760 in), a longer relative neck (0.313 in vs 0.203 in), a shorter COAL (2.130 in vs 2.260 in), and holds slightly less case capacity (~27.0 gr H2O vs ~31.4 gr H2O).
How does 222 Remington compare with 222 Remington Magnum case dimensions?
Both share the same rim (0.378 in) and base (0.376 in) diameters, but the .222 Remington Magnum is longer in case length (1.850 in vs 1.700 in) and holds more capacity (~34.0 gr H2O vs ~27.0 gr H2O).
How does 222 Remington compare with 221 Remington Fireball case dimensions?
Both share identical rim and base diameters, but the .221 Fireball is a shortened version of the .222 Remington, featuring a 1.400 in case length compared to 1.700 in for the .222 Remington.
What is the 222 Remington maximum pressure?
The SAAMI Maximum Average Pressure (MAP) is 50,000 PSI. C.I.P. establishes maximum pressure (Pmax) at 3,700 bar (53,664 PSI).