Trap shooting: Blue rocks

Question
Paul:
 What are blue rocks made of? Once they contained arsenic, do they still?

Answer
Hi,
The Blue Rock Target is made originally made by the Chamberlin Cartridge Company 1880 to 1933 when Remington Arms Co. bought the The Blue Rock Target.
The original targets were simplt backed clay.
Today they made of pitch and chalk  or asphalt and bituminous or  clay and pine tar  or limestone and pitch.

http://www.shootata.com/about/atahistory.htm
here are the big makers of these targets today
Champion Targets (800) 447-4971
Blue Rock Target     www.remington.com
White Flyer Targets   800-423-6077
Midwest Target Company  (217) 324-4895

Here are some others
http://www.shotgunsports.com/targets.htm

As far as I know All USA targets are eco-friendly and bio-degradable.
Asenic was the used in many products untill the 1940s
it rarely used now.
To the best of my knowldge there has no Asenic in them in my time in the sport 1982 to present.