His name is Jerry Mikulik. From my understanding he started off shooting bowling pins with an 8 3/8 Smith and Wesson. He is employed by Clarks Custom, or was and is also endorsed by Smith and Wesson. You will notice Smith and Wesson usually produces some sort of pistol endorsed by this man. He is a tough competitor even against some of the best semi auto competition shooters.
In the video I believe he is shooting an 8 shot N frame in 38 super during the first two strings. In the third string he may have been shooting a 625 but I am not for certain.
I think what I have written here is pretty accurate information. If its not, someone please correct me.
Be Safe,
Scott