| 6.5mm Creedmoor | ||||||||||||
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Size comparison of some 6.5mm cartridges, left to right: .264 Winchester Magnum, 6.5×55mm Swedish, 6.5×52mm Carcano, .260 Remington, 6.5mm Creedmoor, 6.5mm Grendel
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| 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 gr H2O (3.40 cm3) | |||||||||||
| Rifling twist | 1-8″ (203 mm) | |||||||||||
| Primer type | Large rifle, Small rifle (Lapua and Starline brass) |
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| Maximum pressure (C.I.P.) | 63,100 psi (435 MPa) | |||||||||||
| Maximum pressure (SAAMI) | 62,000 psi (430 MPa) | |||||||||||
| Ballistic performance | ||||||||||||
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| Test barrel length: 28 inch[not in citation given] Source(s): Hornady,[1] SAAMI,[2][3] C.I.P. [4][5] |
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The 6.5mm Creedmoor, designated 6.5 Creedmoor by SAAMI, 6,5 Creedmoor by the C.I.P. or 6.5 CM or 6.5 CRDMR for short, is a centerfire rifle cartridge introduced by Hornady in 2007[6] as a modification of the .30 TC,[7] which was based on the .308 Winchester[8]. It was designed specifically for long-range target shooting,[6] although it is also achieving success in game hunting.[7] Bullet for bullet, the 6.5mm Creedmoor achieves a slower muzzle velocity than longer cartridges such as the 6.5-284 Normaor magnum cartridges such as the 6.5mm Remington Magnum. However, due to its 2.825 inches (71.8 mm) overall length, it is capable of being chambered in short-action bolt-action rifles and AR-10 semi-automatic rifles.
Contents
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Design considerations[edit]
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[2] or trajectory[9] 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[edit]
This is a medium power cartridge often compared to the .260 Remington and 6.5×47mm Lapua.[10] Three hundred yard energy using 129 grain Hornady SST bullets is listed by an independent reviewer as 1641 ft. lbs.[11] For the 140 grain bullet at 2700 feet per second initial velocity another reviewer reports an MPBR[12] 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.[13] SAAMI test data confirms 6.5 mm Creedmoor (fifteen feet 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).[2] Long-range shooter Ray “RayDog” Sanchez summarized 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).[14]
Handloading[edit]
Only the very longest 140gr bullets will even reach the neck shoulder junction. Right to left: is a 123gr A-Max and Remington 140gr. Calipers are set to magazine length.
Handloading cost for the 6.5 Creedmoor is roughly equivalent to other 6.5mm cartridges, such as the 6.5×47mm Lapua, due to the availability of Lapua small primer brass for both cartridges.[15][16] Norma now makes brass for the cartridge and as of 2017 Norma brass is available through several major retailers at approximately the same cost as Lapua brass. Lapua brass for 6.5×47 lasts about 12 to 20 reloads.[17] Starline sells brass cases with either large or small primer pockets, with small pocket brass costing slightly more.[18] 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[19] but later ones list it as 57,000 psi.[20] This is because Hornady reduced the loads in its factory ammo because of complaints that it was often blowing primers.[21]Lapua delivered Creedmoor brass at Shot show 2017,[22] and production quantities became available via major retailers in second quarter 2017. The Lapua version has a small primer pocket.[15][23] Thus, loads from a Lapua Creedmoor should not be used in another manufacturer’s Creedmoor brass that features a large primer pocket without applying proper hand loading test for pressure first. Also the use of a smaller diameter decapping rod is required to size and decap.
Further developments[edit]
From left: 6mm Creedmoor, 6.5mm Creedmoor, .308 Winchester
The 6mm Creedmoor is a necked-down version of the 6.5mm Creedmoor using 6mm (.243 inch) bullets, which are lighter than 6.5mm bullets with similarly reduced recoil. John Snow at Outdoor Life designed it in 2009. As of May 2018, Savage Arms offers 3 bolt action rifles and 1 semiautomatic rifle chambered in 6mm Creedmoor.[24] As of May 2018, Hornady offers 87 gr Varmint Express, 103 gr Precision Hunter and 108 gr Match ammunition in 6mm Creedmoor.[25]
Military use[edit]
In October 2017, U.S. Special Operations Command tested the performance of 7.62 NATO, .260 Remington, and 6.5 Creedmoor cartridges out of SR-25, M110A1, and Mk 20 sniper rifles. SOCOM determined that 6.5 Creedmoor performed the best, doubling hit probability at 1,000 meters, increasing effective range by nearly half, reducing wind drift by a third and having less recoil than 7.62 NATO rounds. Because the two rounds have similar dimensions, the same magazines can be used and a rifle can be converted with a barrel change. This led to its adoption and fielding by special operations snipers to replace the 7.62 NATO cartridge in their semi-automatic sniper rifles, planned in early 2019. In response to SOCOM’s adoption, the Department of Homeland Securityalso decided to adopt the round.[26][27]