We all know that chamber pressure rises when we shoot in real hot weather, but my question is why? Is it because of a hot barrel, cartridge,or both? Does the powder being hot play a role? When the barrel expands, does it expand evenly and does the bore get smaller? If the bore gets smaller and bullet expands, the bore/bullet relationship becomes tighter, and is that where the pressure comes into play? I have my own theories, but I don't know if I've ever seen it in print. Oh...the hot dogs and babes? Just seeing if you're awake. Thanks, ciao.