SIG Rattler, now in 7.62x39mm for SOCOM?
SOCOM– which earlier this year for up to $5 million worth of “Reduced Signature” PDW weapons in the form of modified commercial SIG MCX Rattlers in both 5.56 NATO and .300 Blackout– posted the notice for 7.62x39mm uppers for the platform in late October.
“Due to developing requirements,” explains the notice, the force at the tip of the spear is seeking conversion kits to include all “required hardware and ammunition magazines that will fit with the SIG Sauer Rattler and RSAR/PDW converted M4A1 lower receiver groups.”

SOCOM may be in luck as SIG recently debuted their first 7.62×39-chambered offerings in the MCX Spear-LT series. One of the options in that series is a factory SBR with an 11-inch barrel and an overall length of 29.75 inches, something that puts the company within striking distance of the RFI notice.
More in my column at Guns.com.