Recently the United States Special Operations Command awarded a 5-year IDIQ contract to SIG SAUER for MCX Rattlers in .300BLK to be used as Reduced Signature Assault Rifle (RSAR)/Personal Defense Weapons (PDW).
However, the MCX SPEAR-LT and its variants can quickly be converted to the initially offered 5.56 NATO caliber, or more recently 7.62×39, which has been in service with allied units for some time now. Although envisioned since its inception, the 7.62×39 capability was first publicly shown in 2015.
In light of this capability, USSOCOM has issued a Sources Sought Notice to industry for “7.62 x 39mm upper receiver caliber conversion kits that are compatible with the SIG SAUER Rattler Lower Receiver. The upper receiver caliber conversion kits shall integrate with the SIG SAUER Rattler and RSAR/PDW converted M4A1 Lower Receiver Groups. The conversion kits shall include all required hardware and ammunition magazines that will fit with the SIG SAUER Rattler and RSAR/PDW converted M4A1 Lower Receiver Groups….the vendor shall provide spares for the whole RSAR/PDW system to include but is not limited to bolts, springs, 7.62 SLHC suppressors, UTM training kits, stocks, carrier groups etc.”
They are seeking a 7.75″ barrel with a weapon featuring an Overall Length with Stock folded of 18.4″. The Upper Receiver with flash hider installed must not exceed 16.4″.