Stop doing bad McCree math. He's doing theoretically 25% more dps on PTR, not 20%.
Every McCree thread I open I see the number 20% being thrown out, and the people posting even have the audacity to downvote and "correct" posters who try to point out it's actually 25%. Yes, the time between shots is going down by 20% (.5 to .4 seconds), but his shots per second is thereby increasing from 2 shots per second to 2.5 shots per second, which is obviously a 25% increase (2*1.25=2.5). Since his shot damage hasn't changed, shots per second is directly proportional to damage per second, and there you go.
EDIT: I probably should have ignored DPS and just talked about his rate of fire. The patch notes decrease the period between shots, which is just the inverse of frequency/rate (seconds per shot vs. shots per second), so the period goes down by 20% and his rate goes up by 25%. So not only is it is wrong to say he is doing 20% more damage, it's also wrong to say he's shooting 20% faster.
EDIT 2: Okay yeah, my math is only slightly less bad. I didn't bother with reloads, so this discussion is only pertinent for his dps/rate of fire in a single reload, which is still pretty damn important since he can kill most of the cast in a single reload.
*Okay Final Edit: We might as well do reloads too since there's confusion. According to the Overwatch wiki, McCree's reload time is 1.5 seconds. Therefore on live with reloads he shoots 6 times in 4.5 seconds (6 rounds divided by 2 shots per seconds plus 1.5 reload time), so a rate of 1.3333... shots per second. Reload time hasn't changed on PTR so now he shoots 6 times in 3.9 seconds (6 rounds divided by 2.5 shots per second + 1.5 reload time), so a rate of about 1.54 shots per second. This is about a 15% increase in overall fire rate/damage rate. I probably made some mistake or missed some other assumption BUT 20% IS WRONG AND STOP REPEATING IT IN EVERY MCCREE MEME THREAD.
*Oh wait u/owisawesome just corrected themselves before I posted the last edit, but the math is still the same, thank you211 Read the full article on Reddit