The exigencies of modern special warfare operations are mandating operational enhancements across the spectrum of combat equipment. Examples of these recent and pending enhancements can be found within the small arms arena, where personnel at the Naval Surface Warfare Center (NSWC) Crane Division, have focused some recent development activities on the creation of new 7.62mm and .300 Winchester Magnum sniper rounds.
Speaking before the recent National Defense Industrial Association (NDIA) small arms systems symposium in Las Vegas, Nev., Jarod D. Stoll, NSWC – Crane, described the development efforts behind one of the new sniper rounds, the 7.62mm, Mk316 Mod 0, Special Ball, Long Range cartridge.
“The project had its origins when there were some accuracy inconsistencies in the M118 Long Range cartridge,” Stoll explained. “An 18-month Joint Working Group was unable to come up with any corrective measures for that cartridge, so we were tasked by our sponsor to develop an alternative cartridge to meet their requirements.”
“Some of the objectives we had for this cartridge were that we wanted consistent lot-to-lot accuracy and to function in new and existing gas-operated sniper rifles. Also we wanted flash reduction,” he said.
Identification of objectives was followed by the development of detailed specifications.
“One of the principal factors for [the new round development] was centered around accuracy,” he noted. “And our requirement for that was 7 inches extreme spread at the max average of 600 yards and then 3.5 inches max extreme spread at 300 yards.”
Accuracy testing was conducted out of a standard 7.62mm sniper rifle with 22-inch barrel length.
“Also a requirement for velocity standard deviation was set at 15 feet per second maximum,” Stoll continued. “We also desired to have a flash reduced and temperature stable propellant. We wanted comparable performance, velocity and chamber pressure from -25 degrees [F] to + 165 degrees [F]. Each lot was to consist of a single lot of projectiles, propellant and primers to ensure consistency across lots and within a lot.”
“We then proceeded on to the solicitation for a new contract. This was a full and open competition. We challenged industry to come up with the best 7.62mm cartridge that they could. We opened the projectile weight up to 150-200 grain. Then we required that they submit product bid samples, where we tested them, compared them to each other for accuracy, pressure, velocity, etcetera,” he said.
The competition resulted in the selection of a candidate from Federal Cartridge Company.
David Leis, from Federal Cartridge Company, spoke about his company’s development process behind the selected round.
“Typically bench rest or match ammunition is utilized in bolt action single shot rifles, not in semi-automatic, magazine-fed, militarized rifles,” Leis explained. “So much work had to be done developing port pressure, action time, getting the overall length so that the cartridge would feed from the magazine, etc. In addition, match ammunition is not really designed to be used at 165 degrees. In initial testing we saw that the chamber pressure would jump as much as 60 percent, so a lot of development needed to be done on that. In addition, we wanted to optimize the maximum effective range, so we were hoping for a cartridge that would be supersonic past 1,000 yards.”
Citing his company’s “long history of Gold Medal Match ammunition,” Leis added, “We were hoping to use our history and expertise to develop a cartridge to meet this requirement.”