USP 40 springs

[RCPerkins]

I just purchased a secondhand H&K USP 40. My problem is that the previous owner bought a set of Wolff springs for reduced power loads and I don't know which are which. How can I tell?

 

[IM_Lugger]

if you're talking about recoil springs I'd shoot both and see whch one throws the brass farther that one will be reduced.

 

[maurice]

I would think .40 recoil spring would be stronger than 9mm in the USP series. If it is not throwing it far enough, than go lighter. I am guessing he replaced the larger spring only, and left the buffer spring (the small hard one). The USP could use a really light spring,..as the little spring takes all the abuse. THE USP was one of the best feeding pistols I ever owned, you could ride the slide home and it would feed no matter how slow you went.