I thought HSTs had a cannelure, but cannelure or not, whenever I eject a live round from a magazine-fed firearm it goes into the range ammo box.

I never thought about how normal temperatures might effect bullet performance. Ammo storred in the car trunk in 100* summers (where temps can soar) or -30* winters might have an adverse effect, but I would never have thought that a temperature range where one might comfortably work or play would have any kind of impact on performance. On this one I remain skeptical.