What pistol & rifle calibers can I use?

As with all other shooting targets you can technically use whatever caliber or type of firearm you want to use. These targets have 121 individual pockets of powder. So you could technically shoot these 121 times with a smaller caliber firearm and hit each pocket separately. However more then likely a shot will damage multiple pockets thus lowering the quantity of shots per target. So to answer this question, you can use whatever caliber you want, the large calibers will cause more damage and send more powder. 

How many time can I shoot the target and expect a reactive powder spray?

As with the question above, this is all relative and depends on the caliber you use and the shot placement. Technically you could shoot each target 121 times due to there that many individual pockets of powder. However the chances of being able to hit each pocket separately are pretty slim, so we would say on average you could maybe get 30-50 shots per target depending on the caliber used.

Is the powder harmful to the environment?

The powder is responsibly dyed cornstarch and fully biodegradable. The cardboard targets are also fully biodegradable. The H Frame stand is, of course, metal. Please reuse and enjoy.

Is there a warranty on the Sput Targets?

Giving a warranty on a target is hard due to their being so many different conditions and elements that can change for each situation. Therefore once the sealed package is opened, we do not warranty the Sput Targets. We offer a return policy for all unopened, still vacuum sealed packages that are returned to us.