HK USP9 reducer plug

thingiverse

I created this Grip Plug for my HK because it's challenging to find HK parts where I live. Instead of waiting for a Reduced Power Main Spring (10/11lbs), I reduced the Pretension on the Original Spring (ca.14lbs). This works great while dry firing, and I'll try it on the range next week. The 3.5mm Plug worked just fine, with less Pull weight, but the 5.5mm had some light primer strikes with the stock firing pin spring. The Original pull weight is ca. 3.6kg / 7.9lbs; internals polished. The 3.5mm reducer pull weight is ca. 3.2kg / ca. 7lbs, which works fine with Ammo used: Geco 124gr FMJ and Fiocchi 123gr FMJ. The 4.75mm should get you to ca. 2.9kg / ca. 6.4lbs; not tested yet. Ammo used is the same as before: Gevo 124gr FMJ and Fiocchi 123gr FMJ. I made it in two different "spring-hole" depths. In the future, I'll design one with a special screw for variable settings. Stay safe.