The .22 Creedmoor is a short-action centerfire rifle cartridge featuring a maximum case length of 1.920 inches (48.77 mm) and a maximum overall cartridge length of 2.700 inches (68.58 mm). Based on official SAAMI standardization approved in 2024, the case features a 0.473 inch rim diameter, a 0.470 inch base diameter, a 0.462 inch shoulder diameter, and a maximum neck diameter of 0.256 inches. Published specifications can vary slightly depending on whether they represent maximum material conditions, nominal dimensions, or specific brass manufacturer tolerances.
22 Creedmoor Case Dimensions
| Case Dimension | Inches | Millimeters | Specification Type | Source | Notes |
| Case Length | 1.920 | 48.77 | Maximum | SAAMI | Standard trim to length is 1.910 in. |
| Rim Diameter | 0.473 | 12.01 | Maximum | SAAMI | Standard short action bolt face. |
| Rim Thickness | 0.054 | 1.37 | Maximum | SAAMI | Controls extractor engagement. |
| Base Diameter | 0.470 | 11.94 | Maximum | SAAMI | Measured just above the extractor groove. |
| Shoulder Diameter | 0.462 | 11.73 | Maximum | SAAMI | Body to shoulder intersection. |
| Neck Diameter | 0.256 | 6.50 | Maximum | SAAMI | Outside case neck diameter. |
| Shoulder Angle | 30° | N/A | Half Angle | SAAMI | Retains the 30 degree Creedmoor family shoulder. |
| Overall Cartridge Length | 2.700 | 68.58 | Maximum | SAAMI | Allows feeding from short action magazines. |
| Case Capacity | ~52.6 | 3.41 cm³ | Nominal (H2O) | Industry Std. | Varies by brass manufacturer and wall thickness. |
| Maximum Pressure | 62,000 | 427.47 MPa | Max Average | SAAMI (Piezo) | Established during 2024 SAAMI acceptance. |
Understanding The .22 Creedmoor Case Dimensions
To understand how the .22 Creedmoor interacts with a rifle chamber, bolt, and magazine, you must analyze its discrete geometric components. Each dimension serves a specific engineering purpose.
- Case Length: Measured from the base of the rim to the case mouth, case length determines how far the brass extends into the chamber before contacting the end of the neck clearance.
- Rim Diameter and Thickness: The rim provides the gripping surface for the rifle extractor. The diameter ensures the cartridge centers on a standard short action bolt face, while the thickness affects how securely the extractor engages the brass.
- Base Diameter: This is the widest part of the main cartridge body, situated just ahead of the extractor groove. It governs how the cartridge seats into the rear of the chamber.
- Shoulder Diameter and Geometry: The shoulder acts as the physical stop that prevents the cartridge from pushing too far into the barrel. Its diameter and 30 degree angle dictate chamber fit and headspacing.
- Neck Diameter: The neck holds the bullet. The outside diameter must clear the chamber walls to allow the brass to expand and release the projectile safely upon firing.
- Overall Cartridge Length (OAL): The measurement from the case base to the tip of the seated bullet. It dictates magazine fit and whether the bullet will prematurely engage the rifling lands.
- Case Capacity: The internal volume of the case, generally expressed in grains of water (gr H2O). This dictates the maximum powder charge the cartridge can safely hold.
.22 Creedmoor Case Dimensions In Inches And Millimeters
Official standardization utilizes inches, but metric parameters are frequently referenced by international shooters and brass manufacturers.
| Dimension | Measurement (Inches) | Measurement (Millimeters) |
| Maximum Case Length | 1.920 in | 48.77 mm |
| Maximum Rim Diameter | 0.473 in | 12.01 mm |
| Maximum Base Diameter | 0.470 in | 11.94 mm |
| Maximum Shoulder Diameter | 0.462 in | 11.73 mm |
| Maximum Neck Diameter | 0.256 in | 6.50 mm |
| Maximum Overall Length | 2.700 in | 68.58 mm |
.22 Creedmoor Case Length
The published maximum case length for the .22 Creedmoor is 1.920 inches (48.77 mm). This matches the case length of its parent cartridge, the 6.5 Creedmoor.
Because brass flows forward under the extreme pressures of firing and resizing, a fired and full length resized case will frequently measure longer than a factory new case. Therefore, handloaders universally utilize a trim length of 1.910 inches. This nominal case length provides a 0.010 inch buffer, ensuring consistent chamber fit, uniform crimping, and safe bullet release without pinching the case mouth into the rifling.
.22 Creedmoor Base And Rim Dimensions
The .22 Creedmoor features a rimless, bottleneck design. Its base diameter measures 0.470 inches, while the rim diameter is slightly wider at 0.473 inches.
This 0.473 inch rim diameter is identical to the .308 Winchester family. It dictates that the cartridge fits a standard short action bolt face. The rim thickness (0.054 inches) determines how well the bolt extractor claw can grip the cartridge during the extraction process.
.22 Creedmoor Shoulder And Neck Dimensions
Above the straight taper of the body, the case steps down to grip a .224 caliber bullet. The shoulder diameter at the intersection of the case body is 0.462 inches. From there, the brass angles inward at a steep 30 degree half angle to meet the neck.
The neck diameter reaches a maximum allowable SAAMI specification of 0.256 inches. To safely release a .224 inch bullet, the chamber neck must be slightly wider than the cartridge neck. A loaded cartridge typically measures around 0.254 inches at the neck depending on the brass wall thickness.
.22 Creedmoor Case Capacity
Case capacity heavily influences internal ballistics, powder selection, and pressure generation. The nominal, industry accepted capacity for the .22 Creedmoor is 52.6 grains of water, or roughly 3.41 cubic centimeters.
This massive powder capacity relative to the small .224 caliber bore makes the cartridge highly overbore. Case capacity is not a static specification. It is a physical measurement that fluctuates between brass manufacturers. Because external dimensions are strictly controlled by chamber sizes, any variation in the thickness of the brass walls directly alters the internal volume.
.22 Creedmoor Case Dimensions vs Similar Cartridges
The .22 Creedmoor exists in a competitive landscape of high velocity .22 caliber centerfire cartridges.
| Cartridge | Case Length | Base Diameter | Shoulder Angle | Neck Diameter | Overall Length |
| .22 Creedmoor | 1.920 in | 0.470 in | 30° | 0.256 in | 2.700 in |
| 6.5 Creedmoor | 1.920 in | 0.470 in | 30° | 0.295 in | 2.825 in |
| 6mm Creedmoor | 1.920 in | 0.470 in | 30° | 0.276 in | 2.800 in |
| .22-250 Remington | 1.912 in | 0.470 in | 28° | 0.254 in | 2.350 in |
| .223 Remington | 1.760 in | 0.376 in | 23° | 0.253 in | 2.260 in |
| .22 ARC | 1.525 in | 0.441 in | 30° | 0.256 in | 2.260 in |
.22 Creedmoor vs 6.5 Creedmoor Case Dimensions
The .22 Creedmoor is a direct descendant of the 6.5 Creedmoor.
They share identical case lengths (1.920 inches), base diameters (0.470 inches), rim diameters (0.473 inches), and the signature 30 degree shoulder angle. The only dimensional difference resides in the neck. The .22 Creedmoor features a neck diameter reduced to 0.256 inches to hold a .224 caliber bullet, whereas the 6.5 Creedmoor features a wider neck diameter for a .264 caliber bullet. Due to the smaller projectile, the maximum overall cartridge length of the .22 Creedmoor is also shorter (2.700 inches versus 2.825 inches).
.22 Creedmoor vs .22-250 Remington Case Dimensions
The .22-250 Remington is the historical benchmark for high velocity .22 caliber cartridges.
While both utilize a 0.470 inch base and a 0.473 inch rim, the .22 Creedmoor features a slightly longer case (1.920 inches versus 1.912 inches) and a steeper shoulder (30 degrees versus 28 degrees). The most significant difference is the overall length. The .22 Creedmoor is designed around a 2.700 inch overall length to accommodate long, heavy for caliber bullets, while the older .22-250 Remington maxes out at 2.350 inches, restricting it to lighter, shorter bullets.
.22 Creedmoor Chamber And Case Dimensions
A rifle chamber must be fractionally larger than the cartridge it accepts. The relationship between .22 Creedmoor case dimensions and chamber dimensions centers heavily on headspacing.
Headspace for the .22 Creedmoor is measured from the bolt face to a specific datum line on the 30 degree case shoulder. When the firing pin strikes, the case expands to seal the chamber. If the case dimensions are too small relative to the chamber, the brass will stretch aggressively to fill the void, thinning the material near the base. If the case dimensions are too large, the bolt will not close.
.22 Creedmoor Case Forming And Resizing
Before SAAMI standardized the .22 Creedmoor in 2024, handloaders formed their own brass by mechanically resizing 6mm Creedmoor or 6.5 Creedmoor cases.
This process involves forcing the larger brass through a specialized sizing die that reduces the neck diameter to 0.256 inches.Because all Creedmoor cases share the same 1.920 inch length and 30 degree shoulder, modifying 6mm Creedmoor brass only requires a single pass through a sizing die to constrict the neck.Necking down 6.5 Creedmoor brass requires more extreme reduction and often necessitates neck turning to prevent the brass walls from becoming too thick for the chamber.
.22 Creedmoor Manufacturer Specifications vs Actual Measurements
There is a documented difference between absolute SAAMI standards and the dimensions of a physical cartridge sitting on a reloading bench.
SAAMI lists maximum material conditions. Ammunition manufacturers intentionally produce brass slightly smaller than these maximums to guarantee their cartridges will chamber in any rifle, regardless of how tightly the manufacturer cut the chamber. A fired .22 Creedmoor case expands to the exact dimensions of the specific rifle chamber it was fired in. When a handloader runs this fired brass through a full length sizing die, the machine compresses the base, shoulder, and neck back down to factory nominal tolerances.
Common Questions
What are the .22 Creedmoor case dimensions?
The key maximum case dimensions for the .22 Creedmoor include a 1.920 inch case length, a 0.473 inch rim diameter, a 0.470 inch base diameter, a 0.462 inch shoulder diameter, and a 0.256 inch neck diameter.
What is the .22 Creedmoor case length?
The maximum SAAMI case length for the .22 Creedmoor is 1.920 inches (48.77 mm).The standard trim to length for reloading is 1.910 inches.
What is the .22 Creedmoor rim diameter?
The .22 Creedmoor rim diameter is 0.473 inches (12.01 mm).
What is the .22 Creedmoor base diameter?
The base diameter of the .22 Creedmoor, measured just above the extractor groove, is 0.470 inches (11.94 mm).
What is the .22 Creedmoor shoulder diameter?
The maximum shoulder diameter of the .22 Creedmoor is 0.462 inches (11.73 mm).
What is the .22 Creedmoor neck diameter?
The maximum outside neck diameter of the .22 Creedmoor is 0.256 inches (6.50 mm).
What is the .22 Creedmoor case capacity?
The nominal case capacity of the .22 Creedmoor is 52.6 grains of water, or 3.41 cubic centimeters. Actual capacity varies depending on the brass manufacturer wall thickness.
What is the .22 Creedmoor overall length?
The maximum overall cartridge length for the .22 Creedmoor is 2.700 inches (68.58 mm) under SAAMI specifications.
How does .22 Creedmoor compare with 6.5 Creedmoor case dimensions?
The .22 Creedmoor shares the exact same case length, base diameter, rim diameter, and shoulder angle as the 6.5 Creedmoor. It simply features a neck reduced to 0.256 inches to hold a .224 caliber bullet.
How does .22 Creedmoor compare with .22-250 case dimensions?
Both cartridges share a 0.470 inch base and 0.473 inch rim, but the .22 Creedmoor features a slightly longer case length, a steeper 30 degree shoulder, and a significantly longer overall length of 2.700 inches compared to the .22-250 Remington maximum of 2.350 inches.
What is the .22 Creedmoor maximum pressure?
The SAAMI maximum average pressure for the .22 Creedmoor is 62,000 psi (piezo method).