Recoil springs are certainly routine maintenance on a 1911.Are you sure you're not limp wristing it????
Oh come on now, somebody was going to say it eventually! I'm kidding of course. I think that recoil springs are a regular maintenance item on 1911's. My first 1911 was a beautiful SW1911PD that has since been sold to a good Friend of mine. If I were in the market for another 1911 it would be at the very top of my list.
2500 rounds for Govt (5"), 1500 for Commander (4.25") and 500 for Officer (compact) are the general rule of thumb for recoil springs for optimum reliability.
It was either 16 or 18. I'd go 18 with +p loads and 16 with any other factory carry/defense load if it were me. If I ever carry mine I'll swap springs, the load I shoot is for competition only. So ya it's barely over major power factor and needs a lighter spring.
It was an 18 with a 23 lbs. mainspring.
Weak springs are the most common cause of malfunctions in a 1911.