Our High Load spring for the CZ Bren 2S and 2MS gas piston is designed to reduce the bolt velocity on both “1 – Normal” and “2 – Adverse” gas system settings. By increasing both the pre-load and spring rate acting on the gas piston rod we are able to delay the unlock time of the carrier and bolt, which in turn reduces the pressure in the barrel at unlock and ultimately reduces bolt velocity. This is a direct replacement for the factory piston spring (#10 on factory manuals).

We have tested many different piston spring designs with ALL current 556×45 and 762×39 Bren 2S and 2MS configurations/barrel lengths. We selected this particular design because it maintains 100% reliability in all weapons tested with all ammunition tested.

With our High Load spring installed you can expect to see more consistent ejection from the 8″-11″ guns and less gas at the ejection port from all barrel lengths.

• Reduced Bolt Velocity
• Direct Fit for Bren 2S and 2MS in 556×45 and 762×39

Designed and Manufactured completely in USA.