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piston

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 wall.

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Recent contents
  1. T22

    Ruger SR556 piston

      1. For Sale
    • $1250
    • Sherwood
    • Oregon
    Used Likes PMC M855 (2910 FPS) and Federal 50 grain varmint tips (3035 FPS). POF roller cam pin Geissele maritime bolt catch Radian raptor charging handle Magpul grip B5 stock Ambi safety Strike industries multi function end plate Strike industries reversible sling attachment ASR flash hider...
  2. WinterBaer45

    AAC Evolution suppressor piston .45

      1. For Sale
      2. For Trade
    • $45
    • Portland
    • Oregon
    Advanced Armament Corporation Evolution suppressor piston .45 16x1mm Right Hand Thread New in box I ordered this to mount onto a HK Mark 23 but its for the wrong suppressor and won’t work for me. $70 part I will sell for $45 or trade for anything cool.
  3. dmmv

    Sig Spear LT 5.56

      1. For Sale
    • $2000
    • NW Portland
    • Oregon
    Listing an Sig Sauer Spear rifle chambered in 5.56 in order to purchase a full size Dan Wesson DWX. Comes with Magpul FDE sights. Asking $2k for a quick sale, meet at A Cut Above Pawn. Alternatively, someone purchase the 15 DWX mags and Acro P2 I have saved up so I can stop dreaming about the...
  4. I

    Sig 516 contract overrun upper

      1. For Sale
    • $700
    • Albany
    • Oregon
    This is an Sig 516 14.5” contract overrun upper receiver with a VG6 delta flash hider pin and welded to bring it over 16”. These uppers have CHF chrome lined barrels and full auto bolt carriers. The piston has 3 gas settings. I took it out once to zero it and do some accuracy testing, put...
  5. Screach

    BNIB Sig MCX Spear LT 16in Complete Upper

      1. For Sale
    • $1400
    • Beaverton
    • Oregon
    Hey all, looking to sell my Spear LT 16” upper in 5.56. It started life as a full size LE/Mil 16” rifle. Barrel has been replaced with a brand new unfired 16” 5.56 barrel. Upper and bolt components have seen 50 rds, barrel is unfired. The LE/Mil versions come with iron sights and a reviewer...
  6. moderndave

    Sig Sauer 716 patrol (piston)

      1. For Sale
      2. For Trade
    • $1400
    • Canby
    • Oregon
    Sig 716 Patrol 308 Have shot 200 or less rounds. Very nice shooting with a suppressor.
  7. mbenz007

    Sig Sauer 14.5 upper

      1. For Sale
    • $875
    • Poulsbo
    • Washington
    Hello, This is a brand new Sig 516 piston upper. Factory 14.5 not pinned or welded. Know your laws. Has a safe scratch as seen in pics. Pics show fuss from a gun sock between rails. New never fired or placed on lower. Will ship where legal for $875
  8. ScottInPDX

    SilencerCo 1/2x28 piston

      1. For Sale
    • $50
    • Tualatin
    • Oregon
    New in unopened package, SilencerCo 1/2x28 piston, model AC25. More info: https://silencerco.com/shop/piston/
  9. T

    16" Upper w/ Superlative Arms piston kit

      1. For Sale
    • $850
    • PALM BEACH GARDENS
    • Other
    AR15 16" Upper w/ Superlative Arms piston kit, AXTS charging handle, and BCM vert grip. $1,200 shipped.
  10. cvande

    Dead Air P Series Booster Assembly w/ 1/2 x 28 piston

      1. For Sale
    • $280
    • Eugene
    • Oregon
    Complete booster assembly (including spring)for Wolfman with 1/2 × 28 piston. Only selling as I do not use on my 509 tactical anymore. No trades.
  11. AdoboArsenal

    Wolf A1 14.5 complete upper - *Price Drop*

      1. For Sale
    • $400
    • Beaverton
    • Oregon
    *Price drop* Selling my Wolf A1 14.5 5.56 complete upper. Based on the T91 Service rifle for the Taiwanese Military. Handguard has been slightly modified to accommodate an Mlok Vertical foregrip, cantilever mount for mounting a weapon light, and a QD sling mount. Includes BCM grip, Cantilever...
  12. DIYshooter

    Hard to find Sig MCX 11.5 Virtus. Grey 5.56 Pistol

      1. For Sale
    • $3200
    • Puyallup
    • Washington
    I have a lightly used Sig Sauer MCX Virtus 11.5” barrel length pistol. I would be surprised if I put 200rds through it. It shows very light wear if you look close (probably not noticeable to most). I love this gun and I’m only selling to finance another MCX build I’ve been working on for a...
  13. meltdown79

    Adams Arms mid-length drive rods -- swap for carbine or rifle length

      1. For Trade
    • Hillsboro/Westside PDX
    • Oregon
    I have some brand new and used Adams Arms mid-length piston drive rods. I'm looking to trade 1:1 for carbine or rifle length drive rods.
  14. W

    PWS MK116 MOD 1-P Piston Rifle, AR15, BRAND NEW!! Primary Weapons Systems

      1. For Sale
    • $1000
    • Scappoose
    • Oregon
    $1000. PWS MK116 MOD 1-P Rifle, BRAND NEW!! Including Factory Case. 16” Barrel with PWS Compensator, Caliber: .223 Wylde, Forward Assist, PWS Long Stroke Piston System, 3 setting Adjustable Gas Regulator PWS Enhanced Buffer Tube with ratchet lock castle nut and end plate set with built-in...
  15. Vorpalis

    Dead Air Ghost/Wolfman Piston, M14.5x1 LH,

      1. For Sale
    • $50
    • Oregon City
    • Oregon
    Selling a Dead Air Ghost/Wolfman piston, M14.5x1 LH thread pitch. Used, but in great condition. These retail for $89, but I'm only asking $50. Prefer cash, face-to-face in the Portland Metro area.
  16. T

    SUPERLATIVE ARMS .750 PISTON KIT

      1. For Sale
    • $280
    • Portland
    • Oregon
    For sale is a brand new Superlative Arms .750 Clamp on Carbine Length Adjustable Piston Kit. Never used. Comes with an extra Op-Rod in Pistol length. Paid $355 for kit and extra Op-Rod Asking $280 or best offer
  17. M

    SilencerCo Piston for sale

      1. For Sale
    • $20
    • Vancouver
    • Washington
    I have a new not opened SilencerCo piston 16M x 1 LH. SKU is AC28-123575 Asking $20 I can ship if needed
  18. Dirtydowg31

    PWS MK114 Alpha on anderson lower + Ammo!

      1. For Sale
      2. For Trade
    • $1850
    • REDMOND
    • Oregon
    had it for about 5 months and ran 2 mags great shooter. This is a piston driven rifle from what I understand the upper is pretty rare. Only available on Saturdays but I am willing to deliver! Pm for more info or any questions you may have!! $50 will go towards NWFA!!!!. Specs: 14.5 pinned and...
  19. clanhanson

    Steyr AUG A3 M1 w/PA 2x Prism

      1. For Sale
    • $2250
    • Helena
    • Montana
    Howdy, I have two AUGs and one needs to go. The one for sale is standard (Steyr mags) with an extended rail. It includes one 30 round magazine (not the 42 round one pictured, sorry), a Primary Arms Glx 2x prism scope, original boxes for the rifle and optic, original tools, and manuals. No...
  20. C

    BRN-180 Upper or BRN-180S Upper

      1. Want to Trade For
    • Seattle
    • Washington
    Title says it all. Only looking for the upper. Gen 1 or Gen 2 doesn't matter Looking to trade although I may throw in some $$$ if the price is right My trades can be found here and here two06 - 9two9 - fivefour80
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