What do you think about those reusable heat bags, they heat up to 50°C (122°F),
if you put them in your pocket near your slingshot to keep the rubber at a very high temperature, it should perform much better, especially at cold days.
I will try it, and put it in my slingshot bag. If one used an insulating bag (eg. to keep cold stuff cool) and put the heat bag and slingshot into it together, it should have a good effect, plus in summer, it doesn't melt your body...
if you put them in your pocket near your slingshot to keep the rubber at a very high temperature, it should perform much better, especially at cold days.
I will try it, and put it in my slingshot bag. If one used an insulating bag (eg. to keep cold stuff cool) and put the heat bag and slingshot into it together, it should have a good effect, plus in summer, it doesn't melt your body...