Army weapons officials are defending their decision to stop the service’s improved carbine competition early, saying that none of the eight participating gun makers performed well enough to replace the M4 Carbine.

“I want to make it very clear none of the vendors met the minimum requirements which allowed them to pass into” the final phase of the competition, Brig. Gen. Paul Ostrowsk, the head of Program Executive Office Soldier, said during a June 14 briefing with reporters.

Program officials began making plans several weeks to find other uses for what amounts to more than $300 million the service has budgeted for new carbines through 2018, Military.com reported May 2.

But Army officials maintain that the Army’s reliability requirement for the Individual Carbine effort proved unreachable for Adcor Defense Inc., Beretta, Colt Defense LLC, FNH-USA, Heckler & Koch, Lewis Machine & Tool, Remington Defense and Troy Defense.

Testers fired thousands of rounds though each vendor’s carbines, but none were able to achieve 3,592 mean rounds without malfunctioning established in the requirements document.

The current M4 series was designed to meet a requirement written in 1990, which called for the M4 to fire 600 mean rounds between stoppages, PEO Soldiers officials said.

“We know that that M4 is performing outstandingly downrange,” said Fred Coppola, deputy project manager for Soldier Weapons. “The intent of the competition was to try to find something that was superior to the M4 carbine. The Army is not really looking for a small improvement; we wanted to see a superior improvement.”

In a June 13 announcement, PEO Soldier officials said that the test weapons’ performance may have been affected by how well each weapon, magazine and ammunition work together.

“The Army’s existing carbine requirement assumed use of the M855 ammunition; the weapons tested in the IC competition all fired the next generation M855A1 Enhanced Performance Round currently in fielding,” the June 13 press release stated. “The use of the M855A1 round likely resulted in lower than expected reliability performance.”

But Army weapons officials backed away from that statement at Thursday’s briefing.

“We have not done the forensics on those weapons to determine any exact event cause per vendor,” Ostrowski said. It would be premature for us to tell you exactly what the issue was because we simply don’t know. … This is a surprise to all of us.”

The Army supplied more than 10,000 M855A1 rounds for gun makers to shoot through their test weapons to identify any problems before the competition, PEO Soldier officials said.

It’s still unclear how close any of the competitors came to reaching requirement 3,592 mean rounds between stoppages. Weapons officials did say that the M4A1, the special operations version of the M4, achieved 1,691 mean rounds between stoppages when it the tested using the new M855A1 ammunition.

The question that still remains unanswered is how did the eight competitors perform when compared to the M4A1, the weapon the Army recently chose as a replacement for the service’s 483,000 standard M4s.

Weapons officials have no plans to make that information public.

“That information is really proprietary; if the vendors choose to release that information then that is there choice,” Coppola said. The Army’s decision to stop the competition came despite a recent House Armed Services Committee budget amendment aimed at preventing the Army from canceling it without conducting the final, soldier evaluation phase.

It’s been five years since Army leaders announced the plan to search for a replacement for the M4 Carbine, originally made by Colt Defense LLC.

“The results were unexpected,” Ostrowski said. “We are continued to continue to work with industry and we are steadfast in that commitment. … Our budgets are tight, but our commitment to ensuring that our soldiers have the best available equipment to provide battlefield overmatch is insatiable.”