Quarter Circle 10’s new Adjustable Pistol Caliber Buffer Assembly sets a new standard for buffers. Adjustable for use with most pistol caliber carbines, suppressed or un-suppressed, 9MM, .40 S&W or .45ACP, the quick change weight management provide optimum reliability in multiple configurations.

The Package Includes: 4 aluminum weights, 4 steel weights, 4 tungsten weights, 4 rubber spacers, buffer body and Allen key. The rubber spacers cut noise and reduce bolt bounce in rapid fire.

These can be mixed and matched to achieve the precise weight that works with your current configuration. Add a can? Change caliber? By removing a single screw, this QC10 buffer adapts to provide exactly what you need.

Quarter Circle 10 Adjustable Pistol Buffer Assembly: The Perfect Tool For Tuning Your Pistol Caliber AR
QC10 Adjustable Pistol Caliber Buffer Assembly


  • 8620 Steel construction and QPQ nitrite finish for maximum wear and durability
  • Easy user adjustability from 5-11oz with included Aluminum, Steel, and Tungsten weights
  • Threaded retaining pin and included allen key eliminates need for hammer and punch
  • Extended length for increased bolt catch life (no spacer necessary)
  • Drop-in installation
  • For use in carbine length buffer tubes
  • Ideal for tuning your Pistol caliber AR for the best function, felt recoil, and sound suppression

I have seen custom AR builders make their own buffers like this to determine the best weight for their rifles. QC10 makes that kind of scientific tuning available to the little guy. It is fast and simple. The roll pin in the regular buffer has been replaced with a simple screw.

***For pistol caliber blow back builds only. The body of the buffer is longer than a milspec AR buffer, sized to prevent bolt over travel in pistol calibers. The polymer tip is blue so it is easily distinguished from your other buffers.

If you already have an AR pistol caliber carbine or rifle, the Quarter Circle 10 dedicated AR15 Adjustable Pistol Caliber Buffer Assembly will make it run better. If you are building a gun, why would you get anything else?

Get your very own QC10 Adjustable Pistol Buffer Assembly –HERE MSRP $120