It wouldn't be too hard for him to master quick draw with more practice.
After all, Bob Munden was an old man who wasn't half as strong and as agile as Luke, but the man could still draw his gun astonishingly fast.
Luke had much more Strength and Dexterity, and he wasn't new to guns. It would be weird if he couldn't grasp quick draw.
He was using a revolver, which was a gun necessary for practicing quick draw.
He had a modified revolver in his inventory, but he couldn't use that Smith & Wesson M500 in public. Also, its barrel had been lengthened, which made it unsuitable for quick draw.
The essence of quick draw was speed and precision. Thus, a common revolver was more suitable for practice.
With his ten-fold Strength and his Elementary Self-Healing, his hands didn't get sore at all.
With his cheat, Luke began to burn through guns as training.
