Question on X-cal2 tones? brass and copper

[glasartisan]

Im currently using a X-cal2 1000 and still have the older X-cal.I use both these machines off the beaten path in waterways.We hunt for prehistoric copper artifacts and very little gold.We are listening for the highest of high tones that the X-cal can give off. The problem is alot of my sites have been in the past been used greatly by duck hunters and of course the great proliferation of the brass end of the shotgun shells they left behind.With my X-cal I have trouble alot of times trying to descrim these out just by using the tone of the X-cal.The copper we find comes real close to the same tone as brass.I hate to crank up the descrim because it takes almost full descrim to knock these brass rounds out.And Im sure I would lose depth also.I tried digging it all but my hunting partner will kill me because of his CZ-21.The brass on his machine actually comes in as a medium tone and most all copper comes in high.2 very destinct tones.Digging only high signals with the 21.
Here is my question;anyone that has dug hundreds of brass end shot shells with the X-cal, can you tell the difference from that and copper? What should I listen for? I thought about slipping a quarter in my boot and use it as a reference tone for when I get a questionable target.
Thanks for all tips, Steve

 

[Paul(Massachusetts)]

What if you took one of the copper targets that you found and superglued that to your boot??

HH
Paul