6.5×47mm Lapua
The 6.5×47mm Lapua (designated as the 6,5 × 47 Lapua by the C.I.P.) is a smokeless powder rimless bottlenecked rifle cartridge that was developed specifically for competition shooting by ammunition maker Nammo Lapua and the Swiss rifle manufacturer Grünig & Elmiger AG in 2005. Other common names for this cartridge include 6.5×47mm. Features. The cartridge has many special features, including: History. The 6.5×47mm Lapua has no direct parent case. It was designed by Lapua with a great deal of help from Swiss rifle manufacturer, Grünig & Elmiger. The case also borrows many characteristics from the 6 mm PPC and has proven itself to be inherently accurate. Cartridge dimensions. The 6.5×47mm Lapua has 3.11 ml (48.0 grains HO) cartridge case capacity. 6.5×47mm Lapua maximum C.I.P. cartridge dimensions. All sizes in millimeters (mm). Americans would define the shoulder angle at alpha/2 = 30 degrees. The common rifling twist rate for this cartridge is 200 mm (1 in 7.87 in), 6 grooves, Ø lands = , Ø grooves = , land width = , and the primer type is small rifle. According to the official C.I.P. (Commission Internationale Permanente pour l'Epreuve des Armes à Feu Portatives) rulings the 6.5×47mm  Lapua can handle up to P piezo pressure. In C.I.P. regulated countries every rifle cartridge combo has to be proofed at 125% of this maximum C.I.P. pressure to certify for sale to consumers. This means that 6.5×47mm Lapua chambered arms in C.I.P. regulated countries are currently (2018) proof tested at PE piezo pressure. Performance. The 6.5×47mm Lapua is a medium power cartridge often compared to the .260 Remington and 6.5 Creedmoor. It was designed from the beginning by Lapua to optimize accuracy, barrel life, and case capacity in a 6.5 mm cartridge for target and tactical shooting. As  such it couples a sensible case volume (3.11 ml) to bore area (34.59 mm/0.3459 cm) ratio with ample space for loading relatively long slender projectiles that can provide good aerodynamic efficiency and external ballistic performance for the projectile diameter. The 6.5×47mm Lapua offers slightly lower muzzle velocities than 6.5 mm/.260 cartridges such as the 6.5 Creedmoor and .260 Remington due to its smaller case volume. In an article by the Precision Rifle Blog a survey of the top 100 shooters in the precision rifle series (PRS) showed that the 6.5 Creedmoor was on average faster than the 6.5×47mm  Lapua. Although the 6.5×47mm Lapua is said to have superior brass quality compared to the 6.5 Creedmoor. The 6.5×47mm Lapua was the most popular cartridge during the PRS competition in 2015 beating out competing cartridges by more than two thirds. C.I.P. rules the 6.5×47mm Lapua and 6.5mm Creedmoor both at up to P piezo pressure and the .260 Remington lower at up to P piezo pressure. Competitions. Competitively the 6.5×47mm Lapua has been setting many records, most of them at . Erik Cortina broke a club record with 6.5×47 Lapua (RL17). Cortina shot a 600-49X ; the previous record was 599-32X. In the summer of 2016 Mike Gaizauskas shot a ten shot group measuring just 2.856 inches at beating out the record previously held by the 6mm Dasher. American Kevin Nevius set a new NRA national record for high power rifle with a perfect score of 200-20X at – 20 shots (Prone-Any Sight). Nevius was using 6.5×47mm Lapua, 136 gr. Scenar-L OTM bullets, and VV N150 powder. The 6.5×47mm Lapua was also the dominant caliber in PRS in 2016, beating out all competing cartridges in the top ten tier, and  dominated the other categories by more than two thirds. The 6.5×47mm Lapua has become very popular with metallic silhouette shooters. The 2014 high NRA Nation Championship equipment survey lists the 6.5×47mm Lapua as second most popular caliber for both the high power rifle and high power hunter rifle competition. The 6.5×47mm Lapua has set a new record in October 2017 for bench rest in the UK with a five shot group measuring 1.058" and on a blustery day at . The old record was 1.437". Variants. Soon after the introduction of the 6.5×47mm Lapua, shooters were using  the case as the basis for a new wildcat, by necking it down to 6 mm. This wildcat cartridge is often called a 6-6.5×47 to avoid confusing it with the 6×47 Swiss Match, a similar case but with a large rifle primer. Another version that has been popular is a necked-down version with a 40-degree shoulder. PTG sells reamers for this and it has demonstrated a gain of about 100 fps over the standard 6-6.5×47.