An abbreviated version of this was published as a
Cartridge Profile in the May/June 2009
Rifle Shooter
 GA Precision fit this 25.3-inch Satern barrel to the author's Accuracy International AWP for
testing Lapua's new 6.5x47 cartridge.
Six point five millimeter has never been a big hit in the United States; however, this is changing
as long-range shooters seek more performance with less recoil. The 6.5-284 Norma is a mainstay
cartridge for long-range target shooters, but it requires a long action and due to its "magnum" case
capacity to bore size ratio, barrel life is short. Up until now, choices for a short-action 6.5 mm
cartridge were pretty limited to .260 Remington and its wildcats like 6.5-08 Ackley. Nammo Lapua
Oy, the famous Finnish component and ammunition manufacturer, recently developed the new 6.5x47
Lapua cartridge specifically for target shooting.
In cooperation with Grunig & Elmiger, Lapua set out to develop a cartridge optimized for European
300-meter CISM competition. Similar to our NRA High-Power, 300-meter CISM has a set course of fire
from defined shooting positions using highly specialized target rifles. The caliber that currently
dominates 300-meter CISM is the 6 mm BR Norma due to its excellent accuracy, good ballistics, and
low recoil. As the project officially started in 2005, two initial project goals were to improve
ballistics by decreasing wind drift and to reduce barrel wear compared to the 6 mm BR Norma, which
will get only about 2500 rounds at top accuracy before the barrel starts to show wear.
6.5 mm cartridges, left to right: 6.5-284 Norma Magnum, .260 Remington, 6.5x47 Lapua.
Stepping up from 6 mm to 6.5 mm gives a clear advantage in wind drift due to the increased BC values
available in 6.5 mm bullets. The increase in bore area significantly extends barrel life over the 6
mm BR Norma. U.S. target shooters got wind of this new 6.5 mm cartridge and suggested some changes,
such as using small primer pockets for accuracy. The final list of design goals included: high
accuracy through quality and consistency, low wind drift and flat trajectory, and low barrel wear.
The resulting 6.5x47 mm case has the same head and body diameter as .308 Winchester and also shares
the same body taper. This allows use of the same magazines, bolts, and actions as the ubiquitous
.308. Lapua set the maximum pressure for the cartridge at 63,090 psi, near the practical maximum
for brass cases. In conjunction with a small primer pocket, the resulting case is very strong.
|
