Image 1 of 1 SIG Sauer M400 DH3 5.56 $1,999.99 Semi-automatic, AR, .233/5.56, 16" Stainless Barrel, Natural Aluminum Finish, DH3 Adjustable Competition Stock, 2 Stage Adjustable Timney Daniel Horner Signature Trigger, Low Profile 3-Gun Handguard. Quantity: Add To Cart Added! Semi-automatic, AR, .233/5.56, 16" Stainless Barrel, Natural Aluminum Finish, DH3 Adjustable Competition Stock, 2 Stage Adjustable Timney Daniel Horner Signature Trigger, Low Profile 3-Gun Handguard.