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piston upper

A piston is a component of reciprocating engines, reciprocating pumps, gas compressors and pneumatic cylinders, among other similar mechanisms. It is the moving component that is contained by a cylinder and is made gas-tight by piston rings. In an engine, its purpose is to transfer force from expanding gas in the cylinder to the crankshaft via a piston rod and/or connecting rod. In a pump, the function is reversed and force is transferred from the crankshaft to the piston for the purpose of compressing or ejecting the fluid in the cylinder. In some engines, the piston also acts as a valve by covering and uncovering ports in the cylinder.

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Recent contents
  1. dlh4x4

    Wolf A1 12.5 5.56 Piston Upper

      1. For Sale
    • $500
    • Lake Stevens
    • Washington
    New in box Wolf A1 T91 short stroke piston upper. Based off the Taiwanese T91 Attaches to any AR15 lower. Chambered in 5.56 Cash, Zelle or Venmo. Shipping available for additional cost.
  2. sparky8

    PWS MK111 PRO long stroke piston upper w/AAC 51t muzzle brake

      1. For Sale
    • $600
    • Newberg
    • Oregon
    Up for sale is a factory PWS MK111 PRO long stroke piston upper with AAC 51t muzzle brake. These PRO uppers are an amazing value for PWS's long stroke piston system and unfortunately PWS just discontinued this line. Very minor salt on a couple MLOK slots from attachments. Here's what you get -...
  3. sparky8

    PWS MK111 PRO long stroke piston upper w/AAC 51t muzzle brake

      1. For Sale
    • $580
    • Newberg
    • Oregon
    Up for sale is a PWS MK111 PRO complete upper with AAC 51t muzzle brake . Less than 100 rounds through this. PWS just discontinued making these PRO series uppers. These are an excellent with PWS's long stroke piston system. Very minor salt on some of the MLOK slots from attachments. Here's what...
  4. E

    Adams Piston Upper

      1. For Trade
    • $400
    • Kent
    • Washington
    Looking to trade 16"Adams piston upper ...for a 18 or 20" DI Keymod or MLok upper. Scope not included.
  5. GI JEW 555

    LMT Piston Upper

      1. For Sale
      2. For Trade
    • $1800
    • Tacoma
    • Washington
    (Upper only). If new to LMT, this model changes caliber or barrel size very easy.Two bolts and it's ready to swap, in less than 5min. Can be swapped to DI if you wanted instead of piston. Top tier AR and doesn't get much better. MSRP is over 3k on rifle before tax ; if you can find one...
  6. A

    Unfired WOLF T91 Piston Upper 16" with BCG/CH

      1. For Sale
    • $450
    • Bellevue
    • Washington
    Unfired wolf t91 a1 upper , 16” barrel with BCG/CH. 1/7 twist - asking $450 and will ship for extra $25
  7. arakboss

    Adams Arms Piston Upper $350 plus shipping

    https://adamsarms.net/product/16-mid-base-upper/
  8. 38super

    Colt lower /lwrc piston upper

      1. For Sale
      2. For Trade
    • $2200
    • Issaquah
    • Washington
    I have a colt lower B5 stock and grip Single stage drop in trigger Lwrc m6ic enhance 14.7 p/w piston upper Surefire m600 pro light Looking for a glock 19x Rmr type 2 colt 1911 Springfield prodigy full size Or what do you have + or - cash Sorry not for sale in wa
  9. joken

    Complete Piston Upper $349

    https://adamsarms.net/product-category/uppers/complete-piston-uppers/?min_price=0&max_price=1900&new_price=349-1900,&ixwpst[product_cat][]=682&ixwpst[pa_product-type][]=657&ixwpsp=1&title=1&excerpt=1&content=1&categories=1&attributes=1&tags=1&sku=1&ixwpsf[taxonomy][pa_product-type][show]=set&ixwp...
  10. I

    14.5" 5.56 Aero Precision M4E1 Enhanced Piston upper w/BCG&CH

      1. For Sale
    • $725
    • Tacoma
    • Washington
    EDIT: its in the title but not the description, so adding here; the caliber is 556 This is the rare-ish Aero Precision/Superlative Arms collaboration. Comes from the manufacturer with a piston kit as well as pinned and welded for the 14.5". I had Aero Precision swap out the barrel for a...
  11. O

    PSA Magpul STR Lower, WOLF A1 16” piston upper

      1. For Sale
      2. For Trade
    • $800
    • Portland
    • Oregon
    For sale is my piston AR15. Lower is the complete Psa ar15 lower with str Magpul furniture, and their EPT enhanced polished trigger. The upper WOLF A1. Rear sight is the magpul buis. Both the upper and lower have exactly 90 through them, the rifle not even precisely zeroed yet, only function...
  12. AmanSlayman

    Aero/Adams Arms 10.5 piston upper

      1. For Sale
    • $600
    • Sherwood
    • Oregon
    Aero m4e1 lower, lpk, milspec Adams arms piston upper Samson evo rail, adjustable gas block 10.5 Ballistic Advantage Barrel I would also seperate upper for $400, lower $200 Like 200 rounds through this, playing around with different settings, I just kept the gas block on fully open most of the time
  13. rayrunspdx

    Wolf A1 14.5 upper - Modernized

      1. For Sale
    • $550
    • Beaverton
    • Oregon
    Selling my Wolf A1 upper 14.5. Handguard has been lightly and tastefully modified to allow QD sling attachment, cantilever mount for a weapon light, and drilled holes for mlok attached BCM vertical foregrip all included. Also has a Midwest Industries fixed rear sight. About 200-300 rounds fired...
  14. maxximo

    7.5" AR Pistol with Adam Arms Piston Upper

      1. For Sale
    • $600
    • Clackamas
    • Oregon
    Up for sale AR-15 Pistol with Adams Arms piston upper and PSA lower. Very reliable and a lot of fun to shoot Optics included $600 obo Will split Transfer fee
  15. Phillyfresno

    Custom Recce Vltor A5 Lower, Superlative Piston Upper

      1. For Sale
    • $1600
    • Brookings
    • Oregon
    Lower: Vltor A5 (Vulcan) Lower but no bless noticed. Fitted with LWRC Ambi Safety and trigger gaurd, Larue MBT2S Trigger, and Geiselle Maritime bolt catch/ checkered Takedown pins. LWRC Compact sopmod style stock. Upper : Aero with FN button chrome lined 16” barrel, superlative Piston kit with...
  16. A

    Sig 516 14.5" Gen 2 Piston Upper w/PSA Complete Lower

      1. For Sale
    • $1050
    • Lake Oswego
    • Oregon
    Selling a very lightly used complete AR pistol setup - has about 200 rounds through the upper w/zero issues. Works perfectly! Includes: - Sig 516 14.5" Gen 2 Piston Upper - Palmetto State Armory Complete Lower Receiver w/Stock & Buffer Assembly - ready for brace. Willing to part out either...
  17. djharteloo

    11.5 pws mk111 pro piston upper, aero lower, trijicon mro

      1. For Sale
      2. For Trade
    • $1100
    • Yacolt
    • Washington
    Bought this upper a few months ago to try one out and the whole build doesn’t get used. 11.5 inch barrel, long stroke gas piston with 4 gas settings, 10 inch mlok handguard, radian raptor lt charging handle. Lower is Aero with an Aero lower parts kit, sba3, B5 systems grip, and with the castle...
  18. Unka-Boo

    14.5” Wolf T91 piston upper

      1. For Sale
      2. For Trade
    • $500
    • Milwuakie
    • Oregon
    This pains me a little, but I’m putting this up to fund a different upper. I have put right around 100 rounds through this, eats just about anything. Prefers heavier bullets ( 1:7 twist ). I am left handed....this upper does not have a case deflector, getting pelted in the cheek is annoying as...
  19. P

    Adams Arms EVO Tactical Complete Piston Upper

      1. For Sale
    • $550
    • Kirkland
    • Washington
    Complete upper with all OEM parts: barrel, BCG, charging handle. The upper is the exact same as: 16" Carbine Tactical Evo Upper Condition and package: Essentially new condition, total 200-300 rounds through it (shot brass and steel cased), no problems at all. Comes with all original parts and I...
  20. JBSTRD

    PWS Mk111 Mod 2-M Complete Piston Upper

      1. For Sale
    • $1200
    • Washougal
    • Washington
    I have a lightly used (approx 100 rounds) PWS MK111 Mod 2-M complete upper. This upper is chambered in 223 Wylde and the barrel length is 11.875”. Comes complete with proprietary long stroke gas piston BCG, PWS branded Radian Raptor LT charge handle, 3 position adjustable gas block, and gas...
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