Piston Kit Bundle - P Series Adjustable Micro Block Mid Length & 15.5" P Series Rail

Product Code: KitRail

Availability: Out of stock

Piston Kit Bundle - P Series Adjustable Micro Block Mid Length & 15.5" P Series Rail


SPECIAL! P Series 15.5" Rail with Mid Length Piston Kit -- WHILE SUPPLIES LAST!

This system will work with .223/5.56 x 45 mm NATO.

Kit includes:

  • Patented One-Piece Bolt Carrier
  • P Series Micro Block - Adjustable (5 Settings - 100%/74%/53%/32%/11%)
  • Upper Receiver Bushing
  • Bushing Installation Rod
  • Bolt Spring
  • Drive Rod with Bushing and Spring
  • Installation Instruction Card

The Adams Arms Piston System:

  • A short stroke free floating piston system.
  • Is Self-Cleaning.
  • Carbon and gases are expelled forward, away from operator.
  • Corrosive resistant coating processes.
  • Harmonics are not transferred into the barrel.
  • Doesn't vent directly to atmospheric pressure; this eliminates flash signature and super sonic crack which is optimal for night vision and suppresses fire.
  • Has a Lifetime Warranty.


To select the correct length kit, use the following measurements:

  • Pistol: 4.846" from barrel extension to shoulder
  • Carbine: 7.866" from barrel extension to shoulder
  • Mid: 9.866" from barrel extension to shoulder
  • Rifle: 13.241" from barrel extension to shoulder
  • For 300BLK we only recommend a Pistol Gas Length and a Low Mass Carrier for optimal performance.

We recommend using a standard barrel nut or barrel nut with similar measurements for proper fit and function of the kit. Many aftermarket proprietary barrel nuts do not offer the clearance for the drive rod or proper seating of the spring and bushing.

Micro Gas Blocks should have the set screws torqued to 87 in-lbs

Installation Instructions: CLICK HERE

The new Adams Arms P Series M-LOK Rail was designed for our new P Series Lineup of rifles. Designed and engineered to be multi-purpose, the P Series Rail has a rigid and ergonomic design and features that make this the best choice for everyday enthusiasts, avid shooters, 3-gun competitors, law enforcement, military, and everything in between. This rail is compatible with any of the Adams Arms low profile piston systems and most standard mil-spec AR-15 rifles.


  • Full length lightened picatinny rail
  • M-LOK® attachment points at 3, 6, and 9 o'clock
  • 4 QD attachment points
  • Weight-reduction cuts
  • Ergonomic finger grooves


  • Length: 15.5""
  • Material: 6061 T6 Aluminum
  • Inside Diameter: 1.290""
  • Outside Diameter: 1.667""
  • Gas Block Clearance: Height 1.011"", Width .450""
  • Weight: 10.528 oz (14.3 oz with barrel nut & hardware)


  • P Series M-LOK Rail
  • Proprietary Barrel Nut
  • Anti-Rotation Insert with 6-32x.1875 Screw
  • (2) 8-32x.375 Screws
  • (2) 8-32 Hex Nuts