The 6.5 Creedmoor is a highly popular short-action centerfire cartridge with a nominal bullet diameter of 0.264 inches (6.71 mm), a standard case length of 1.920 inches (48.77 mm), and a maximum overall cartridge length of 2.825 inches (71.76 mm). This exact primary 6.5 Creedmoor size chart covers standardized physical cartridge dimensions as established by SAAMI. It is designed to provide precise measurements of the casing and projectile, not a general guide to the velocity or bullet-drop performance of individual ammunition loads.
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6.5 Creedmoor Size Chart and Dimensions
| Measurement | Inches | Millimetres | Description |
| Bullet Diameter | 0.264 in | 6.71 mm | Nominal projectile diameter |
| Land Diameter | 0.256 in | 6.50 mm | Approximate bore diameter across the lands |
| Groove Diameter | 0.264 in | 6.71 mm | Approximate bore diameter across the grooves |
| Case Length | 1.920 in | 48.77 mm | Length of the cartridge case |
| Overall Cartridge Length | 2.825 in | 71.76 mm | Maximum standardized cartridge length |
| Rim Diameter | 0.473 in | 12.01 mm | Diameter at the case rim |
| Base Diameter | 0.470 in | 11.94 mm | Diameter near the case head |
| Shoulder Diameter | 0.462 in | 11.73 mm | Diameter at the case shoulder |
| Neck Diameter | 0.295 in | 7.49 mm | Diameter at the case neck |
| Shoulder Angle | 30 degrees | N/A | Standardized shoulder angle |
| Primer Type | Large/Small Rifle | N/A | Standard primer specification (often Large Rifle, though Small Rifle brass exists) |
6.5 Creedmoor Cartridge Dimensions Explained
Bullet Diameter
The nominal projectile diameter used by the 6.5 Creedmoor is 0.264 inches (6.71 mm). This measurement refers exclusively to the width of the bullet itself, which is much narrower than the main body of the cartridge case that holds the gunpowder.
Case Length
The standard case length of the 6.5 Creedmoor is 1.920 inches (48.77 mm). This measures the brass casing from the base (head) to the mouth of the neck, excluding the bullet, and is critical for ensuring the brass fits safely into the rifle’s chamber headspace.
Overall Cartridge Length
Overall cartridge length, often abbreviated as OAL, measures the complete 6.5 Creedmoor from the base of the brass case to the very tip of the seated bullet. The maximum SAAMI specified overall length is 2.825 inches (71.76 mm), which ensures the complete cartridge will fit and feed reliably from standard short-action magazines.
Case Head, Base, and Rim Diameter
The case head is the solid rear portion of the cartridge, featuring a rim diameter of 0.473 inches (12.01 mm) and a base diameter (just ahead of the extractor groove) of 0.470 inches (11.94 mm). These dimensions dictate the bolt face required to properly grip and extract the cartridge from the rifle.
Shoulder and Neck Dimensions
The case shoulder transitions the wider body of the cartridge down to the narrower neck, featuring a steep 30-degree shoulder angle and a 0.462-inch (11.73 mm) diameter. The neck diameter, measuring a maximum of 0.295 inches (7.49 mm) with a seated bullet, is the portion of the brass that securely grips the 0.264-inch projectile.
Bore and Groove Diameter
Within the rifle barrel, the land diameter (the raised portion of the rifling) is roughly 0.256 inches (6.50 mm), while the groove diameter (the recessed portion) is 0.264 inches (6.71 mm). The bullet is sized to match the groove diameter, allowing the lands to engrave into the projectile to impart spin; these two measurements are not interchangeable.
6.5 Creedmoor Size Compared With Other Cartridges
| Cartridge | Bullet Diameter | Case Length | Maximum Overall Length | Key Size Difference |
| 6.5 Creedmoor | 0.264 in (6.71 mm) | 1.920 in (48.77 mm) | 2.825 in (71.76 mm) | The baseline short-action 6.5mm cartridge. |
| .308 Winchester | 0.308 in (7.82 mm) | 2.015 in (51.18 mm) | 2.810 in (71.37 mm) | Uses a wider bullet and a slightly longer case, but fits similar magazines. |
| .243 Winchester | 0.243 in (6.17 mm) | 2.045 in (51.94 mm) | 2.710 in (68.83 mm) | Has a narrower bullet and longer case, sharing the .308’s parent case family. |
| 6.5 PRC | 0.264 in (6.71 mm) | 2.030 in (51.56 mm) | 2.955 in (75.06 mm) | Uses the same bullet diameter but features a noticeably wider, longer magnum case. |
| .260 Remington | 0.264 in (6.71 mm) | 2.035 in (51.69 mm) | 2.800 in (71.12 mm) | Shoots the same diameter bullet but uses a longer case based on the .308 Winchester. |
| 6mm Creedmoor | 0.243 in (6.17 mm) | 1.920 in (48.77 mm) | 2.800 in (71.12 mm) | Identical case family but necked down to accept a narrower 6mm (.243) bullet. |
Note: Cartridges with similar physical dimensions are not necessarily interchangeable. Always use ammunition specifically chambered for the firearm, as chamber pressures and internal geometries vary significantly.
Is 6.5 Creedmoor a 6.5mm or .264-Caliber Cartridge?
The 6.5 Creedmoor is considered both a 6.5mm and a .264-caliber cartridge. The “6.5” in the name refers to the nominal metric bore size class (the land diameter of 6.50 mm), while the actual physical bullet it fires measures exactly 0.264 inches (6.71 mm) in diameter. Metric cartridge names are often approximations or nominal classifications rather than perfectly direct mathematical conversions of the projectile’s exact width.
6.5 Creedmoor Size Compared With Bullet Size
It is important to distinguish between the various components that make up 6.5 Creedmoor measurements. The bullet diameter (0.264 inches) is the width of the actual metal projectile that travels down the barrel. The cartridge case diameter (up to 0.470 inches at the base) is the width of the brass casing that holds the gunpowder. The complete cartridge length (up to 2.825 inches) includes both the brass case and the seated bullet together. Additionally, bullet weight, measured in grains, dictates the mass of the projectile, not its width; a 120-grain bullet and a 140-grain bullet for the 6.5 Creedmoor both share the exact same 0.264-inch physical diameter, but differ in length and internal profile.
Frequently Asked Questions
1. What are the dimensions of a 6.5 Creedmoor cartridge?
The standardized dimensions of a 6.5 Creedmoor include a case length of 1.920 inches (48.77 mm) and a maximum overall cartridge length of 2.825 inches (71.76 mm). The base diameter measures 0.470 inches (11.94 mm), and the case features a 30-degree shoulder angle.
2. What is the bullet diameter of 6.5 Creedmoor?
The 6.5 Creedmoor uses a standard projectile diameter of 0.264 inches, which translates to 6.71 millimeters. This bullet size must match the groove diameter of the rifle’s barrel for safe and accurate firing.
3. How long is a 6.5 Creedmoor case?
An empty, unprimed 6.5 Creedmoor brass casing measures 1.920 inches (48.77 mm) in length. This dimension is critical for ensuring the case fits properly within the rifle chamber’s headspace without pinching the bullet.
4. What is the overall length of a 6.5 Creedmoor cartridge?
The maximum overall length (OAL) of a fully loaded 6.5 Creedmoor cartridge is 2.825 inches (71.76 mm). This size allows the cartridge to fit perfectly within standard short-action rifle magazines.
5. Is 6.5 Creedmoor the same as .264 caliber?
Yes, the 6.5 Creedmoor fires a .264-caliber projectile. The “6.5” designation references the approximate metric land diameter of the bore, while .264 inches is the true measurement of the bullet itself.
6. How wide is a 6.5 Creedmoor cartridge case?
The widest part of the 6.5 Creedmoor case body is the base, which measures 0.470 inches (11.94 mm) in diameter. The rim, which sits just behind the extractor groove, is slightly wider at 0.473 inches (12.01 mm).
7. Is 6.5 Creedmoor bigger than .308 Winchester?
The 6.5 Creedmoor is not bigger than the .308 Winchester; in fact, it uses a narrower bullet (0.264 inches vs. 0.308 inches) and a slightly shorter case length. However, both have very similar overall lengths, allowing them to be fired from similarly sized short-action rifles.
8. Is 6.5 Creedmoor the same size as 6.5 PRC?
No, the 6.5 Creedmoor is significantly smaller than the 6.5 PRC (Precision Rifle Cartridge). While both fire the exact same 0.264-inch diameter bullet, the 6.5 PRC uses a much thicker and longer magnum-sized casing designed to hold more gunpowder.
9. What is the difference between bullet diameter and case diameter?
Bullet diameter refers strictly to the width of the projectile being fired (0.264 inches for the 6.5 Creedmoor). Case diameter refers to the thickness of the brass cylinder that holds the powder and primer, which is significantly wider (up to 0.473 inches at the rim) than the bullet.
10. Can 6.5 Creedmoor ammunition be used in another 6.5mm rifle?
No, 6.5 Creedmoor ammunition cannot safely be fired in other 6.5mm rifles, such as the 6.5x55mm Swedish or the 6.5 PRC. Even if the bullet diameter is exactly the same, the cartridge case dimensions are completely different and will not fit the chamber properly.