Sorry; I meant to address the people who have the opinion that factory strength springs should be used.
Remember, the factory spring is a COMPROMISE; Colt's knows some people are going to shoot low power target loads, and full power, or even +P loads without changing the recoil spring. These people would return the gun as faulty if it didn't digest everything fed to it.
This is ridiculous. I use a 10 lb. spring for my 200 gr LSWC loads, which work at about 8,000 lup. My GC's function just fine with this. As noted above I use 20 or 22 lb springs with my full power and +P loads. My pistols function very well with these springs. Tailoring the recoil spring to the load used is one of those things we knowledgeable people can do to optimize reliability and minimize pistol wear.
A .45 Super, which works at 28,000 cup, uses a much heavier recoil spring (34 lb. or so, if I recall correctly). This is in the 1911 pistol.
So, don't make the mistake that the factory power spring is best. It is the best COMPROMISE. You don't need to settle for a compromise. Walt