HB Industries CZ Scorpion EVO 3 Reduced Weight Trigger Spring Kit

The HB Industries Reduced Weight Trigger Spring Kit is the cheapest and safest trigger upgrade on the CZ Scorpion platform, and it should be the default starting point for most owners. The kit contains three parts: a lighter trigger spring, a lighter disconnector spring, and a firing pin safety shim. Together they drop the factory pull weight from approximately 9 pounds to about 5.5 pounds, which is roughly a 40 percent reduction in pull weight while keeping the factory hammer, sear, and trigger geometry entirely unchanged.

The geometry-preserved aspect is what makes this kit important. Full-module aftermarket triggers like the Timney drop-in unit change the hammer reset timing and the rate at which the hammer follows the bolt during cycling. That timing change is the underlying mechanical cause of the platform's documented out-of-battery detonation issue. The factory bolt is soft enough that a faster hammer reset peens the metal around the striker block hole, eventually defeating the in-battery safety. The HBI spring kit avoids that failure mode entirely because it does not change hammer geometry or reset timing; it only reduces the spring force the shooter has to overcome to break the shot.

Two compatibility caveats. First, this kit is NOT compatible with Franklin Armory BFSIII binary triggers; if you plan to run a binary trigger, you need a full BFSIII install (and the Nexus Enhanced Bolt). Second, 2016-2019 Scorpion S1 models had a high rate of factory-welded trigger packs that required a carbide drill to defeat the weld before any spring kit or trigger upgrade can be installed. HBI sells a separate carbide drill kit for this purpose. Newer guns (post-2019) and the Scorpion 3+ ship without the weld and accept the spring kit directly.

For most Scorpion owners, this is the right upgrade path. $13 buys a meaningful pull weight reduction with zero added safety risk. If the spring kit does not satisfy you and you want the cleaner break and shorter reset of a full-module trigger, plan to install the Nexus Enhanced Bolt at the same time.