This should be explained in the "Factory Ammo" section of the stickies, above.
Take the type/brand ammo you would like to be shooting (that which is locally available to you) and then replace the gun's recoil spring with one that is several pounds lighter. IOW, if your gun currently is running a 20lb spring, a conversion to a spring between 14lbs and 16lbs should allow the gun to cycle.
Simply stated... The "power" of the spring is simply chosen to counteract the "power" of the ammunition.
Then, you will insert the stiffer stock spring when you are using high powered "self defense" ammo. And, conversely convert to the lighter spring when on the range practicing with your low-cost, low-power ammo. You will in effect be tunning the gun to the ammo. This is a much lower cost alternative than tunning the ammo to the gun... which would mean buying a reloading setup, learning how to reload, buying hard-to-find components, etc, etc.
Hope this helps.