My G20SF has one or two failures to feed during each 15rd magazine, usually during the second or third round fired. It occurs with all six of my 15 round magazines but not my 10 round magazines. The mags had the older 10 coil springs, which I suspected may have been the culprit, so I replaced them all with Wolff +10% springs. After firing about 300 rounds at the range today, I did not see the problem getting any better. I'm also using a Wolff guide rod and spring. I had a 19lb spring in it during the last range trip and a 20lb in it this time. Both had the exact same issues. During the end of the trip today, I popped the factory recoil spring assembly back in and fired one full mag, plus a few extra rounds with no issues. I would have fired more but I ran out of 10mm ammo at that point. All of the rounds fired were my handloads consisting of a Zero 200gr FMJ with 10.7gr Blue Dot, which chronos at around 1160 fps out of my stock barrel. I would say these are full powered loads, but slightly weaker than Underwood and the like. Has anyone else had lots of failures to feed in their G20s? What type of recoil spring assembly are you using?