• Proprietary Feed Ramp, contoured specifically for 9MM ammunition, ensures feed reliability and increased ammunition compatibility.

• 1/2-28 Threading

• 4150 CMV Steel

• 1-in-10? twist rate

• QPQ Nitride Treated

• Quarter Circle parts are designed to work within mil-spec perimeters.  However, for optimum performance we recommend using QC10 parts for all your core elements, (Receivers, Bolt, Barrel and Adjustable Buffer System).

• Made For - Not Modified.  Every QC10 product is engineered specifically for pistol caliber ammunition, not modified from an existing platform, increasing functionality, reliability and overall performance.

Note:

*Barrels are measured from the end of the muzzle to the end of the breech/feed ramp. Approximately1”  of the barrel rests inside the upper receiver upon installation, resulting in an installed length of 1? less than listed overall length.

*The installation of a pistol-caliber suppressor requires the use of a fixed barrel spacer. See your suppressor manufacturer for information on the requirements of your particular model.