I'm new to this machine so please forgive me. Do bottle caps always burp. Every time I get the burp sound I dig it and its always been a bottle cap. Can I reliably say at this point that when the sov burps its going to be a bottle cap. I am saying this because on my whites machine I've gotten some rings with rocks that sounded like crap but I always knew to dig cause I could hear a good tone within the crappy tone. Thanks