6.5mm Creedmoor

6.5mm Creedmoor

Size comparison of short-action cartridges, left to right: (AR-10 length) .308 Winchester, 6.5mm Creedmoor, .243 Winchester, (AR-15 length) 6.5mm Grendel, .223 Remington
Type Centerfire rifle
Place of origin United States
Production history
Designed 2007
Manufacturer Hornady
Produced 2008
Specifications
Parent case .30 TC
Case type Rimless, bottleneck
Bullet diameter .2644 in (6.72 mm)
Neck diameter .2950 in (7.49 mm)
Shoulder diameter .4620 in (11.73 mm)
Base diameter .4703 in (11.95 mm)
Rim diameter .4730 in (12.01 mm)
Rim thickness .054 in (1.4 mm)
Case length 1.920 in (48.8 mm)
Overall length 2.825 in (71.8 mm)
Case capacity 52.5[1]
Rifling twist 1-8" (203 mm)
Primer type Large rifle
Maximum pressure (C.I.P.) 62,150 psi (428.5 MPa)
Maximum pressure (SAAMI) 62,000 psi (430 MPa)
Ballistic performance
Bullet weight/type Velocity Energy
120 gr (8 g) AMAX 3,020 ft/s (920 m/s) 2,430 ft·lbf (3,290 J)
140 gr (9 g) Hornady ELD-X 2,710 ft/s (830 m/s) 2,283 ft·lbf (3,095 J)
Test barrel length: 28 inch
Source(s): Hornady,[2] SAAMI,[3][4] CIP[5]

The 6.5mm Creedmoor is a centerfire rifle cartridge introduced by Hornady in 2007[6] as a modification of the .30 TC,[7] which was based on the 300 Savage. It was designed specifically for rifle target shooting, [6] although it is also achieving success in hunting.[7] Bullet for bullet it achieves a slower muzzle velocity than longer cartridges such as the 6.5-284 Norma or magnums such as the 6.5mm Remington Magnum. However, due to its 2.825 inch overall length, the 6.5mm Creedmoor is capable of being chambered in short-action bolt rifles and AR-10 rifles.

Design considerations

6.5 mm (.264") bullets, in general, are known for their relatively high sectional density[7] and ballistic coefficients, and have seen success in rifle competition. For some loads the 6.5mm Creedmoor is capable of duplicating the muzzle velocity[3] or trajectory[8] of the .300 Winchester Magnum while generating significantly lower recoil, based on lighter projectile weight. As this cartridge is designed for a bolt face diameter of .473 inches (roughly 12 mm), conversion of a short action rifle to another caliber (such as the .22-250 Remington, .243 Winchester or .300 Savage) with similar bolt face diameter generally requires little more than a simple barrel change.

Performance

This is a medium power cartridge is often comparable to the .260 Remington and 6.5×47mm Lapua but is not as accurate as the Lapua case.[9] Three hundred yard energy using 129 grain Hornady SST bullets is listed by an independent reviewer as 1641 ft. lbs.<ref name JoeA1">D'Alessandro, Joe. "The Ruger M77 Hawkeye - 6.5 Creedmoor Part II Handloading the 6.5 Creedmoor for the M77". RealGuns.com. Retrieved August 22, 2015. </ref> For the 140 grain bullet at 2700 feet per second initial velocity another reviewer reports an MPBR[10] for a six inch high target of 265 yards and reports a manufacturer claim of "almost 1600 ft. lbs." of retained energy at 300 yards using a 24-inch barrel.[11] SAAMI test data confirms 6.5 mm Creedmoor (fifteen foot from muzzle) velocity of 2,940 fps for the 129 grain bullet and 2,690 for the 140 grain bullet (which compares to .300 Winchester magnum data of 2,930 fps for a 200 grain bullet and 2,665 fps for a 210 grain bullet).[3] Long-range shooter Ray "RayDog" Sanchez summarised the bolt-action Tubb 2000 rifle in 6.5mm Creedmoor as "boringly accurate" at 1000 yards (914.4 metres). He asserted the rifle and ammunition combination he used was able to maintain sub-MOA groups at 1000 yards (914.4 metres).[12] The 6.5 Creedmoors accuracy compared to the 6.5x47 Lapua, a cartridge that has nearly identical ballistic performance, falls just a little short for hand loaders. According to Rifleshooter.com’s editor, "In my personal experience, the 6.5×47 Lapua seems to be slightly more accurate than the 6.5 Creedmoor."[13]

Handloading

Handloading for the 6.5 Creedmoor is expensive(compared to the 6.5×47Lapua). Brass often costs $0.068 per reload because it lasts less than 10 reloads on average.[14] Norma now makes brass for the cartridge but it is hard to find and expensive. 6.5×47 lasts about 20-35 reloads.[15] When the 6.5 CM was first introduced it was advertised as a 60,000 psi capable case.[6] However, when it was placed into production Hornady listed it as 62,000 psi and had it SAAMI registered as such. For this reason many hand loaders have had poor experiences reloading for it. Blown primers on the first shot at 62,000 psi is not uncommon. Early shooting articles listed the ammo as loaded to 58,000 psi[16] but later ones list it as 57,000 psi.[17] This is because Hornady reduced the loads in its factory ammo because of complaints that it was often blowing primers.[18]

See also

Notes

External links

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