At this year’s annual AUSA show, SIG SAUER displayed versions of the Product Improvement Effort or PIE guns developed in partnership with the US Army.
The goal of the effort is to address Soldier recommendations for the M7 and M250 along with program requirements. SIG refers to the resulting weapons as the M7 Enhanced Rifle and M250 Enhanced LMG.
The Army conducted several Soldier Touch Points with SIG and conducted a firing schedule to evaluate the PIE versions of the M7 and M250.
The main concern is weight of the M7 rifle and that is where most of the changes are focused. They ended up developing two versions of the PIE M7, a rifle and carbine. The point of the carbine was to accelerate the evolution of the M16 platform which eventually became the M4 carbine and see where they would end up.
The M7 with 13.5″ barrel currently weight 8.3 lbs dry, without ammo, suppressor, or XM157 FCS. The weights for the two PIE variants are:
M7 7.6 lbs
M7 Carbine 7.3 lbs
Although most of the weight difference between the M7 and the Carbine variant is due to a shorter 10″ barrel and handguard, there were several other changes overall.
– The side-folding buttstock has been eliminated, but length remains adjustable.
– The upper receiver and operating system have been refined to eliminate weight.
– Tapered barrel.
The handguard facilitated access to the barrel change bolts which have been slightly strengthened.
The Army is considering whether the Carbine length barrel meets their lethality requirements.
Additionally, there is a lot of talk on the internet regarding barrel life. The program requirement was for 5,000 rounds which is the same specification as the M4. However, SIG has noted barrel life for the M7 in excess of 10,000 rounds.
As for the M250, the changes have been to accommodate Soldier requirements rather than weight as the Automatic Rifle is already lighter than the M249 SAW it replaces.
The changes are:
– Streamlined and improved gas system
– Improved bipod
– Hinged retainable Handguard to accommodate barrel change
– Quick Change Barrel (although they weren’t shown I’ve seen different barrel lengths)
– Extended pic rail on feed tray (optimized for XM157 Fire Control System)
– Cross pins for pintle T&E and mag bloc
– Improved lock and interface for buttstock durability
– Improved magazine which holds the top round in place when it has not yet been fed into the weapon.
– Opened up trigger guard for gloves
The NGSW weapons are chambered in 6.8x51mm and use a common suppressor. SIG also developed a PIE version which is slightly shorter and has a removable heat shield.
The Army is currently evaluating the PIE variants of NGSW to determine if any of the changes will be incorporated into the program. Regardless, the XM157 Fire Control System remains a part of the program and it doesn’t seem to be shedding any weight.
