260 Remington also known as 6.5-08 A-Square cartridge was introduced by Remington in 1997. Many wildcat cartridges based on the .308 Winchester case had existed for years before Remington standardized this round.
Because 6.5mm have relatively high ballistic coefficients, the .260 Remington has seen success in rifle competition including bench rest, metallic silhouette, and long range. It is capable of duplicating the trajectory of the .300 Winchester Magnum, while generating significantly lower recoil. Also, converting a rifle chambered for the .308 Winchester or any of its offspring, such as the .243 Winchester, 7mm-08 Remington, .358 Winchester or .338 Federalto .260 Remington generally requires little more than a simple barrel change.
ORIGIN AND HISTORY
Remington has had a track record of adopting successful wildcat cartridges into the Remington fold by offering rifles and ammunition and at times attaching their name to the cartridge. Like many cartridges such as the .22–250 Remington, .25-06 Remington, and 7 mm-08 Remington. The .260 Remington started its life as a wildcat cartridge called the 6.5-08mm, and was eventually released as a commercial cartridge by Remington. However, Remington was not the first to attempt to standardize the cartridge. LTC Arthur Alphin and his company A-Square LLC submitted the first proposal and drawings to SAAMI for the standardization of the cartridge. Remington filed similar papers with SAAMI to do the same a few months later. When the dust settled, the 6.5-08 would be called the .260 Remington instead of 6.5–08 A-Square. More to that, 6.5-08 cartridge was created simply by necking down the .308 Winchester.Handloaders and wildcatters can easily form .260 cases by necking down the 7mm-08 Remington or necking up the .243 Winchester (both based on the same .308 case), Since the parent cartridges were readily available for low cost, the 6.5-08 was often an economical alternative to cartridges such as the 6.5×55mm. What the 6.5-08 provided over the .243 Winchester, .308 Winchester, and to a lesser degree the 7mm-08 Remington was bullets with excellent ballistic coefficients and sectional densities.
Since the 6.5-08 was a wildcat cartridge, variations existed between cartridge chambers depending on the reamer used to cut the chamber. Furthermore, depending on whether one chose to form the case from .243 Winchester or .308 Winchester influenced the neck thickness and therefore the dimensions of the cartridge. A cartridge formed for a specific rifle may or may not successfully chamber or worse may reach dangerous pressures in another. Standardizing the cartridge addressed the issues owners experienced when it was a wildcat.
.264 (6.5 mm) caliber has historically been commercially unsuccessful in North America but has been one of the mainstays in Europe especially in the Scandinavian countries. The Mannlicher–Schönauer, 6.5×55mm, 6.5×57 Mauser, and 6.5-284 Norma have loyal followings in Europe. Starting with the .264 Winchester Magnum and later the 6.5mm Remington Magnum, North American cartridges in this caliber have been largely failures.
The .260 Remington appeared to be following this North American trend, with Remington only producing the Model Seven Synthetic in the .260 Remington for 2011 as it has discontinued such rifles as the Model 700 CDL and the Model Seven (including the youth model) in .260.
However, Remington continues to manufacture several types of .260 Remington loads. The use of the 6.5×54mm by Sgt Sherri Gallagher to win the 2010 NRA High Power National Championship has sparked a resurgence in the round, and Lapua announced at the 2011 SHOT show that it would be manufacturing .260 Remington brass.
Design and specifications
260 Remington uses the .308 Winchester case as its parent cartridge which is simply necked down to accept a .264 caliber bullet with no further changes made to the case. As the cartridge follows a modern design, it has little taper which allowed its parent cartridge to feed reliably through auto-loading rifles such as the M14, FN FAL and the H&K G3. The .260 Remington has a case capacity of about 3.47 ml (53.5 grains) H2O.
Both SAAMI and C.I.P. have provided design specifications for the .260 Remington cartridge. While there are minor dimensional differences between dimensions provided by both organizations, these dimensional differences mostly fall within the tolerances allowed by the other organization, though C.I.P. lists the .260 as a Delta L problem cartridge. SAAMI dimensions for the cartridge were issued on January 29, 1999, when the Remington’s submission was accepted.