A folding stock is available as an additional option. A modular handguard, ... The SIG MPX-SBR is a registerable 6.5″ NFA short-barreled rifle, legal wherever SBR’s are permitted.

The SIG MPX-P-PSB, which includes a side-folding SBX pistol stabilizing brace, starts at $1,862. The semi-automatic SIG MPX SBR starts at an MSRP of $2,062.

The new MPA SBR, stock folded. %embed1% About the stock: %embed2% The MPA stock works with 930, 30, 10 or 57 series pistol receivers. It secures to the frame w/ ¼-20 threaded hole behind grip on ...