The 7mm Precision Rifle Cartridge (7mm PRC) is a beltless magnum centerfire rifle cartridge featuring a standard maximum bullet diameter of 0.284 inches (7.21 mm). The maximum case length is 2.280 inches (57.91 mm), and the maximum overall cartridge length is restricted to 3.340 inches (84.84 mm) to fit standard long action magnum magazines.The case utilizes a standard magnum rim diameter of 0.532 inches (13.51 mm) and a matching base diameter of 0.532 inches.Ammunition for this caliber is most commonly found in 160 grain, 175 grain, and 180 grain heavy for caliber bullets. Exact dimensions and operating pressures can vary slightly depending on manufacturing tolerances and whether you reference American SAAMI specifications or European C.I.P. standards.
7mm PRC Dimensions
| Dimension | Specification | Source | Notes |
| Bullet Diameter | 0.284 in (7.21 mm) | SAAMI | Standard for 7mm centerfire projectiles. |
| Case Length | 2.280 in (57.91 mm) | SAAMI | Maximum case length; trim to length is typically 2.260 in. |
| Overall Cartridge Length | 3.340 in (84.84 mm) | SAAMI | Maximum overall length for standard long action magazines. |
| Rim Diameter | 0.532 in (13.51 mm) | SAAMI | Standard magnum bolt face dimension. |
| Case Diameter (Base) | 0.532 in (13.51 mm) | SAAMI | Measured just above the extractor groove. |
| Shoulder Diameter | 0.519 in (13.18 mm) | SAAMI | Features a modern 30 degree shoulder angle. |
| Neck Diameter | 0.317 in (8.05 mm) | SAAMI | Maximum external diameter at the case mouth. |
| Base Diameter | 0.532 in (13.51 mm) | SAAMI | Uniform with the rim to eliminate the traditional magnum belt. |
| Case Capacity | 80.0 to 82.0 gr H2O | Industry Standard | Varies slightly based on the brass manufacturer and wall thickness. |
| Maximum Pressure | 65,000 psi | SAAMI | Governed by SAAMI specifications for modern magnum rifles. |
Understanding The 7mm PRC Dimensions
- Bullet Diameter: The measurement across the widest point of the bullet. For the 7mm PRC, this is specified as 0.284 inches. This dimension ensures the projectile seals properly within the barrel rifling to trap expanding gases and generate extreme long range velocity.
- Case Length:The length of the empty brass cylinder from the base to the case mouth, maxing out at 2.280 inches. This extended case provides the massive internal volume needed to push heavy 7mm bullets at magnum speeds.
- Overall Cartridge Length (OAL): The total length of the fully assembled round from the base to the tip of the bullet, strictly capped at 3.340 inches. This dimension dictates that the 7mm PRC requires a standard long action to feed and eject properly.
- Rim Diameter: The diameter of the flange at the very bottom of the case measuring 0.532 inches. This is the exact same rim diameter used by traditional belted magnums, meaning rifle builders can use standard magnum bolt faces.
- Case Diameter: The width of the cartridge body at the base. By matching the base diameter (0.532 inches) to the rim diameter, the 7mm PRC eliminated the need for a traditional brass belt.
- Base Diameter: The width of the brass just above the extractor groove. It must withstand the initial expansion of ignition during firing.
- Case Capacity: Measured in grains of water (gr H2O), this represents the internal volume of the empty case. Averaging roughly 80 to 82 grains of water, this cartridge holds enough slow burning powder to propel heavy bullets efficiently.
- Maximum Pressure: The peak internal pressure generated when the cartridge is fired. Standard SAAMI limits set this at a robust 65,000 psi.
7mm PRC Cartridge Dimensions In Inches And Millimeters
For engineers, reloaders, and international shooters, below are the primary 7mm PRC measurements converted accurately between imperial and metric systems.
| Dimension | Inches (SAAMI Max) | Millimeters (Equivalent) |
| Bullet Diameter | 0.284 in | 7.21 mm |
| Case Length | 2.280 in | 57.91 mm |
| Overall Length | 3.340 in | 84.84 mm |
| Rim Diameter | 0.532 in | 13.51 mm |
| Base Diameter | 0.532 in | 13.51 mm |
| Shoulder Diameter | 0.519 in | 13.18 mm |
| Neck Diameter | 0.317 in | 8.05 mm |
7mm PRC Case Dimensions
The 7mm PRC is defined by a massive, beltless, bottlenecked case derived directly from the 375 Ruger parent case.The official maximum case length is 2.280 inches (57.91 mm), with a nominal trim to length for reloaders sitting at 2.260 inches.The base diameter measures 0.532 inches, blending seamlessly into the 0.532 inch rim.
Because the 7mm PRC case eliminates the traditional magnum belt found on older 7mm cartridges, it offers superior chamber alignment. The case walls expand perfectly centered within the chamber. The steep 30 degree shoulder angle also prevents the brass from flowing forward into the neck during firing, which drastically extends the reloading life of the brass and maintains consistent internal case capacity around 80 to 82 grains of water.
7mm PRC Bullet Diameter
The standardized maximum bullet diameter for the 7mm PRC is 0.284 inches (7.21 mm). This specific bore diameter gives shooters access to a massive inventory of incredibly aerodynamic, high ballistic coefficient 7mm projectiles.
The standard 7mm PRC barrel features a groove diameter of 0.284 inches and a bore diameter of 0.277 inches. Firing a 0.284 inch bullet down a 0.277 inch bore diameter forces the copper jacket to engrave tightly into the rifling. The 7mm PRC is explicitly chambered in barrels with fast twist rates, such as 1:8, to properly stabilize modern bullets that are exceptionally long and heavy.
7mm PRC Overall Length
The SAAMI maximum overall cartridge length (OAL) for the 7mm PRC is 3.340 inches (84.84 mm). This maximum overall length is a defining dimensional characteristic of the cartridge, allowing it to fit effortlessly into standard long action rifle magazines.
Historically, older cartridges like the 7mm Remington Magnum were restricted to this same 3.340 inch OAL but featured longer cases. This forced manufacturers to seat long, aerodynamic bullets dangerously deep inside the brass case, which displaced gunpowder and compromised accuracy. The 7mm PRC fixes this. By utilizing a shorter 2.280 inch case, the 7mm PRC allows massive 175 grain and 180 grain bullets to sit farther forward, maximizing powder capacity and ensuring the bullet enters the barrel rifling perfectly aligned.
7mm PRC Chamber And Cartridge Dimensions
The relationship between the 7mm PRC cartridge and the firearm chamber is engineered for extreme precision. Unlike older belted magnums that headspace inconsistently on a brass belt, the 7mm PRC headspaces entirely on its 30 degree shoulder.
This means the angled portion of the brass casing physically stops against a matching machined angle inside the barrel chamber. This provides a precise, solid stopping point that aligns the bullet perfectly concentric to the bore. Because the cartridge is designed for heavy target bullets, the chamber throat or freebore is cut much longer than traditional hunting rifles to accommodate the elongated ogive of modern match projectiles without jamming them into the lands.
7mm PRC Dimensions vs Similar Cartridges
To understand the 7mm PRC size profile, it is helpful to compare it against other popular magnum rifle cartridges.
| Cartridge | Bullet Diameter | Case Length | Overall Length | Base Diameter | Maximum Pressure | Source |
| 7mm PRC | 0.284 in | 2.280 in | 3.340 in | 0.532 in | 65,000 psi | SAAMI |
| 7mm Rem Mag | 0.284 in | 2.500 in | 3.290 in | 0.512 in | 61,000 psi | SAAMI |
| 300 PRC | 0.308 in | 2.580 in | 3.700 in | 0.532 in | 65,000 psi | SAAMI |
| 6.5 PRC | 0.264 in | 2.030 in | 2.955 in | 0.532 in | 65,000 psi | SAAMI |
| 28 Nosler | 0.284 in | 2.590 in | 3.340 in | 0.550 in | 65,000 psi | SAAMI |
7mm PRC vs 7mm Rem Mag Dimensions
The 7mm PRC was designed specifically to fix the dimensional shortcomings of the legendary 7mm Remington Magnum. While both fire the exact same 0.284 inch bullets, their cases are fundamentally different.
- Overall Length and Throat:The 7mm Rem Mag uses a longer 2.500 inch case inside a 3.290 inch OAL, which forces long bullets deep into the powder column.The 7mm PRC uses a shorter 2.280 inch case inside a 3.340 inch OAL, leaving plenty of room for heavy bullets.
- Case Design: The 7mm Rem Mag utilizes a brass belt near the base for headspacing, which can cause inconsistent chamber alignment and reduced brass life. The 7mm PRC is completely beltless and headspaces cleanly on its 30 degree shoulder.
- Twist Rate and Throat:The 7mm Rem Mag chamber was standardized decades ago for shorter, lighter bullets, typically requiring a 1:9 or 1:9.25 twist.The 7mm PRC features a longer throat specifically cut for heavy 175 to 180 grain bullets and demands a faster 1:8 twist.
7mm PRC SAAMI vs C.I.P. Dimensions
Cartridge dimensions and safe pressure limits are governed by SAAMI in the United States and C.I.P. in Europe.
Hornady successfully submitted the 7mm PRC to SAAMI for standardization in 2022. SAAMI lists the maximum average pressure for the 7mm PRC at 65,000 psi, measured via conformal piezoelectric transducers. C.I.P. also adopted the cartridge, and while they measure pressure slightly differently, the physical dimensional specifications remain identical to ensure global compatibility. Ammunition manufactured to SAAMI specifications is considered safe and standard in any properly chambered rifle worldwide.
7mm PRC Bullet Weight And Dimensions
The 7mm PRC was optimized entirely around the longest, heaviest bullets available in the 7mm spectrum. Common factory bullet weights include:
- 160 grain:Typically loaded as a monolithic copper hunting bullet like the Hornady CX. These solid bullets are physically long for their weight and fit perfectly within the 3.340 inch overall length limit while leaving maximum case capacity for gunpowder.
- 175 grain:Typically loaded for extreme long range hunting. These bullets offer incredible ballistic coefficients and balance velocity with terminal performance.
- 180 grain: Heavy match target bullets designed to stay supersonic at extreme ranges. To maximize the 3.340 inch magazine length, these massive bullets sit largely forward of the case neck.
Bullet weight does not alter the external brass case dimensions, but the manufacturer must carefully manage bullet seating depth to ensure the loaded round takes full advantage of the long action magazine without compressing the powder charge dangerously.
Why 7mm PRC Dimensions Matter
Understanding the specific 7mm PRC measurements is essential for several practical reasons.
- Action Size Requirements:The 3.340 inch overall length means shooters can build a 7mm PRC on a standard long action rifle like those used for the 300 Win Mag or 30-06 Springfield without requiring a massive, heavy magnum action.
- Modern Freebore:The longer chamber throat explicitly engineered into the 7mm PRC specifications prevents dangerous pressure spikes when firing modern, ultra long match bullets that would otherwise jam into the rifling of older 7mm chambers.
- Reloading Consistency: Because the case headspaces precisely on the 30 degree shoulder without a belt, reloaders can easily bump the shoulder back a mere 0.002 inches during resizing. This exact dimensional control creates incredibly accurate ammunition with long brass life.
Manufacturer Specifications vs Independent Measurements
If you use precision calipers to measure factory 7mm PRC ammunition from companies like Hornady or Federal, the numbers will rarely match the SAAMI maximum specifications exactly.
SAAMI publishes maximum allowable dimensions to ensure absolute safety and interoperability across all custom rifle builders. Ammunition manufacturers purposefully produce their cases slightly smaller than these maximums. For example, the maximum case length is 2.280 inches, but measuring a factory cartridge might reveal a case length of 2.268 inches. This built in negative tolerance margin guarantees that the magnum ammunition will chamber smoothly in the field without jamming in tight match grade chambers.
Common Questions
What are the dimensions of the 7mm PRC?
The key maximum dimensions are a bullet diameter of 0.284 inches, a case length of 2.280 inches, and an overall cartridge length of 3.340 inches.
What is the 7mm PRC case length?
The maximum SAAMI case length is 2.280 inches (57.91 mm).
What is the 7mm PRC overall length?
The maximum overall length (OAL) is 3.340 inches (84.84 mm), fitting perfectly into standard long action magazines.
What is the 7mm PRC bullet diameter?
The SAAMI maximum bullet diameter is 0.284 inches.
What is the 7mm PRC rim diameter?
The rim diameter measures 0.532 inches, matching the standard magnum bolt face used by cartridges like the 300 Win Mag.
What is the 7mm PRC case capacity?
The 7mm PRC holds approximately 80.0 to 82.0 grains of water depending on the exact thickness of the specific brass casing.
What is the maximum pressure for the 7mm PRC?
The SAAMI maximum average pressure is strictly capped at 65,000 psi.
How do 7mm PRC and 7mm Rem Mag dimensions compare?
They share the same bullet diameter of 0.284 inches, but the 7mm PRC utilizes a shorter 2.280 inch case compared to 2.500 inches, eliminates the brass belt, and features a modernized 30 degree shoulder and longer throat for heavy bullets.
Does the 7mm PRC use the same bolt face as a 300 Win Mag?
Yes. Both cartridges share the exact same 0.532 inch magnum rim diameter, allowing them to utilize the same bolt carrier group and extractor mechanisms.