I plan on shooting 45 super out of my glock 21 and need a new RSA with a 24lb recoil spring. I was set on the Glockmeister gen 4 RSA, then I noticed it comes with Ismi recoil springs. This concerns me, as I am reading reports that ISMI spring weigjt may not actually be as strong as advertised, and in my case I definitely want/need a legit 24 pound spring. http://www.glockmeister.com/Glockme...r-Gen-4-G20-G21-and-G41/productinfo/G4SS20CS/ Is it possible to swap out the spring on this assembly with a wolff spring? If not, could someone recommend another RSA that would be worth looking at? Im ok with using a Gen 3 RSA with adapter, provided its reliable. Or, should I take a chance and order the Glockmeister RSA in the link?