The OEM B-28 spring is by far much more powerful than the Maccarri replacement spring. But the Maccarri spring is alot smoother and easier to shoot with. Call it an even trade off. I will agree with Gene. You can't abuse any spring an expect it to last long,....not matter if it's RWS, Xisico, or Maccarri. My B-28A is a dream to shoot, and is my favorite hunting rifle. My B-28 (.177) is an absolute Hammer, and must be shot with heavier pellets to stay sub-sonic!!!! I'd recommend the Maccarri spring for the .177 cal, and the OEM for .22. Basically the opposite of what my clones are set up with!!! LOL's tjk