Sig Sauer MPX K 9mm Luger Pistol, 4.5 in Threaded Barrel, Short-Stroke Gas Piston, Custom Isler Handguard, Telescoping Brace, 30+1, Two 30-Round Mags
This Sig Sauer MPX K stands out as a compact, piston-driven 9mm with a 4.5 inch threaded barrel, a multi-port muzzle device, and a custom Isler Custom Gun Works cylindrical vented handguard. It includes a telescoping dual-rod stabilizing brace and two factory 30-round MPX magazines. Marked with correct MPX rollmarks and built in the USA, it combines the MPX operating system with a purposeful custom configuration.
Condition
Overall Condition: Good condition, showing some signs of prior use and handling.
Bore Overall Condition: Excellent - Clean, mirror finish, no signs of wear.
Bore Rifling: Excellent Rifling - Sharp lands and grooves.
Specific Condition Notes: The firearm is in solid shape with visible scratches and blemishes. The top Picatinny rail shows blemishes. The safety selector lever on the right side is not present.
What’s Included
- Isler Custom Gun Works cylindrical vented handguard with an extended top Picatinny rail running nearly the full length of the handguard (installed)
- Telescoping dual-rod pistol stabilizing brace with rear cuff and strap (installed)
- Multi-port/slotted muzzle device (installed)
- Two 30-round SIG Sauer factory MPX 9x19 polymer magazines with steel feed lips
The MPX K configuration delivers a compact footprint with a 4.5 inch barrel and the proven MPX operating system: a short-stroke gas piston with a closed, rotating bolt. It feeds from detachable 30-round MPX magazines for a 30+1 capacity.
The installed Isler Custom Gun Works handguard is a cylindrical, vented design with an extended top Picatinny rail running nearly the full length of the handguard. It complements the MPX upper while maintaining a slim profile around the barrel and muzzle device.
The barrel is threaded and fitted with a multi-port, slotted muzzle device. This setup provides compatibility with common 9mm muzzle attachments while retaining a compact overall length.
Furniture includes a telescoping dual-rod stabilizing brace with a rear cuff and strap, plus an AR-pattern polymer pistol grip. The receiver features a Picatinny top rail, a left-side bolt catch, and a right-side ejection port with dust cover.
Observed markings include "SIG MPX" on the upper receiver, "SIG SAUER INC., USA" on the lower, and "SIG MPX MULTI-CAL" on the lower. Country of origin is the USA.