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JP Adjustable Gas System
A2/M4 sight
.750 bore
Black Stainless
Locking Adjustment

The JPGS-2FS is an A2/M4 front sight assembly that replaces existing pin-on assemblies and provides a gas adjustment. This unit can also be used as a front sight only to extend the sight radius of any existing carbine or rifle.

  • Full coverage around gas port providing improved seal and better heat dissipation
  • True clamp-on design with two positive clamping screws
  • Easy to access side gas adjustment


  • Barrel Diameter: .750
  • Finish: QPQ
  • Weight: 3.9 oz.
  • Material: 416 stainless
  • Weight: 3.9 oz.
  • Length: 1.870"
  • Height: 3.400" (overall), 2.650" (over bore)
  • Width: .870"
  • Attachment: 10-32 x 1/2" socket head screws, 5/32 hex drive
    (includes 5/64" x 5/16" roll pin for gas tube installation)
  • Adjustment: 8-32 x 1/4" stainless set screw, 5/64 hex drive (hex key included)


The installation of this gas block requires use of a 6-32 H1 or H2 bottoming tap. If you do not own such a tap, you can add one to your order at right. Click the link to the JPGS-2FS instruction sheet below for more details.

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Product Instructions

Gas Tube Installation:

Add Bottoming Tap:

Price: $149.95