If using sabots the barrel heat from shooting on a hot summer day can really cause havoc, especially if using BH209 and not swabbing. I was putting my GM54-120 in the truck with the AC on last summer to cool it down. If you must shoot in the summer go early and give the barrel plenty of time to cool down between shots. Its been in the 90's the last few days here. Definitely too hot to shoot IMO.