There was a day when I had enough muscle mass to do this effectively. Adam demonstrates in fine fashion how to load a new round in a single-handed tactical load. You would first drop and shake the mag out, then pop the new mag in for the reload. Adam uses a Glock 23, but with a Glock 20 you would then have 15 rounds of "oh my God" to discharge.

For me, I can do this maybe 1-in-3 times.