tangolima said:
I know. But it just works out better for me to go the other way round. The idea is the slide will stop by the spring alone, never have to hit on the frame metal-to-metal.
But the pistol is designed to let the slide hit the frame (or, more accurately, hit the spring guide flange, which in turn is resting against the frame). The slide hitting the frame won't hurt the gun -- 1911Tuner has proven that by firing some of his pistols with NO recoil spring. And I seriously doubt that your heavier recoil spring actually stops the slide short of contact with the frame anyway. I don't know if I'm even capable of calculating what strength a spring would have to be to accomplish that ut, suffice it to say, it would be WAY more than 20 pounds.
Gong the other way, think about what stops the slide when it returns to battery. On the way forward, it picks up the barrel and the whole mass of the slide and barrel is being slammed forward by a combination of bounce and recoil spring pressure. What stops it? It stops when the two little feet on the underlug of the barrel slam into that .200" slide stop pin. The harder you hit that, the sooner something's going to break. The owner of the M1911.org forum knew a guy who insisted on using an extra-heavy recoil spring ... right up until the entire underlug ripped off from the bottom of his expensive, custom barrel.
Lastly, 1911Tuner has mentioned innumerable times that Browning's patent for the M1911 does not call that round spring in the front of the pistol a "recoil" spring. It's an "action" spring, and its purpose is to close the action, NOT to resist recoil. The original design for the M1911 called for a "recoil" spring that was about 14 pounds. Then it got bumped to 16 pounds, and today we find any number of people who really should know better advising to use 18, 18.5, and even 20-pound recoil springs.
To each his own. People who think they're smarter and know more about the M1911 design than John Browning are on their own.