SIG Sauer has two new but very different M400 series rifles, each boasting a rich set of added features and upgrades from previous models. 


M400 SDI XSeries


This new rifle goes well beyond the standard M400 and includes fully ambidextrous surface controls-- including bolt catch and release, selector switch, charging handle and mag release-- along with a hybrid flash hider/compensator, 2-stage flat blade Matchlite trigger and Magpul SL telescoping Stock. The XSeries-- a designation the company normally sets aside for pistols-- uses lightning cuts in the upper and lower, a full-length PIC rail, and a flared magwell. Meanwhile, the rifle uses a handguard clamp system designed to minimize deflection when using mounted accessories. 


M400 SDI XSeries
The 16-inch 1:7 Chrome-moly barrel uses a low-profile gas block with a mid-length gas system inside an M-LOK handguard. (Photo: SIG)
M400 SDI XSeries
Note the ambi surface controls. (Photo: SIG)




M400 Tread Predator 2


SIG first introduced the original M400 Tread Predator early last year as a 7.5-pound hunting-oriented rifle that included a 1:8-twist 16-inch. stainless steel barrel that was an easy match for a suppressor, a 5-shot polymer magazine, adjustable precision stock, and an alloy forend with an M-LOK accessory rail. 

The new upgrades to the Predator 2 are designed to optimize the gun for use as a varmint/predator getter with a shortened carbine-length (down from a rifle-length) buffer tube system with Magpul's new PRS Lite stock which includes an adjustable cheek comb. The trigger pack is now a 2-stage flat blade Matchlite trigger, and the grip has been swapped out for SIG's Cross series grip. 


The M400 Tread Predator 2 runs a Cerakote Jungle finish. (Photo: SIG)
And weight is a handy 7.4 pounds while overall length is 34.5 inches. (Photo: SIG)




revolver barrel loading graphic