"I don't even know how this thing works, I just know the fire it breaths when it kills a man" would be my answer to anyone that asked me about this .357 Magnum shooting fire rings. Even after reading the description on YouTube I'm still not concerned with how or why it happens, but only how awesome it is. The description is below if you care to try to understand.
Shooting some HOT .357 Magnum loads with the Ruger GP100, 3" barrel. The 125 gr Remington Golden Saber as loaded by Underwood Ammo is a ton of fun to shoot. I typically would get the "ring of fire" effect after the 4th shot in the cylinder; in most cases the 5th or 6th shot. I wonder if the "ring" is caused by an extra-hot barrel.....I'm curious. Temperature during the shoot started at 92 degrees then dropped to 78 for the evening sessions. Humidity was approximately 50%.
I purchased a 50 round box of this ammo for less than $30. Advertised muzzle velocity is 1600 fps, which far exceeds the Remington factory load. My 5 shot average was 1441 fps, from a 3 inch barrel! This actual velocity absolutely crushes the advertised velocity of most 125 gr premium factory loads by a wide margin. It is also very accurate; I was printing baseball-sized groups at 20 yards without much effort, single action.
There will be a gel test of this load at some point. This cartridge should offer excellent terminal performance in a self-defense scenario, but the muzzle flash can be excessive.