IMR 4350 was the powder used that holds the 1000 Yard Any Sight Match Record by a friend.

Open Record Carl B KOVALCHIK SPRINGFIELD, VA 200-19Xs 7/12/1996

He used a 300 Win Mag with a custom min dimension chamber designed by another friend Ray Steele who was Armorer for US Secret Service. Carl was a shooter on the USSS team.

If anyone would like to have a rifle built with that same chamber I have the reamer drawing I got from Ray Steele and had Dave Manson make my reamer. Ray told me it was about the sixth reamer design he worked up for the 300 Win Mag and that was the final one.

Ray went to USSS when Frankford Arsenal closed. He passed about six years and I really miss talking and shooting with him.

If you want to build a rifle with this chamber PM me with a email address and I will send you a copy.