I WOULD LIKE TO KNOW THE DIAM AND LENGTH OF THE RIFLES THAT ARE USED IN THE 500 and 600 MATCHES. THE BARREL MAKERS WHAT DIAM AND LENGTH WOULD YOU TELL THEM TO MAKE A BARREL. I HAVE A STOLLE PANDA ACTION THAT I WOULD LIKE TO BUILD A 6 BR ON TO TAKE TO A MATCH. ANY HELP WOULD BE HELPFUL.