He ain't kidding, read this thing and your life will become fantastic, your hunting life, anyway.
Bottle caps have always been my arch enemy when using the Vaquero and the big DD coil, this method works but you have to turn the knob down to iron and scan it again and that takes too much time so I usually just dig them.
Using my F70 and that same big DD coil this method has proven to be a godsend, and I have eliminated digging at least 90% of these hated things.
No kidding...about 90% or maybe a little more.
A definite 80% but as I get better with practice that number has risen.
I still dig some once in awhile to make sure, and not all of them will react the same way but 90% is huge and it takes no time at all to figure most of them out.
Less time fooling around with these and digging means more time going after the better targets.
I will say with no exaggeration that this is one of the most important techniques I learned and use with my F70 that makes it the most pleasurable and with the least frustration and especially so when hunting areas with tons of these.
Here is how I do it.
Keep in mind that it could happen that you have a good target just north of a bottle cap or another small piece of iron and the effect will seem the same.
This happened to me once, a wheatie was 2" north of a bottle cap and the drop to iron was classic, but in this case I still dug the wheatie because I was in 4H tones and that high tone sounded too good, too clear, too sharp to pass it by so knowing you machine well is paramount as it is when using any detector.
You
must hunt with low disc and leave in iron, these things for me tend to drop to somewhere between 7-12 but sometimes even lower so you have to set your disc to see this effect.
You also can use program 2 with low disc or all metal and just switch over if you want to mostly hunt in higher disc,
I rarely set my disc above 4 and program 2 is always all metal so I can tell when I swing over them in both.
When you pass over these things there are different kinds, some older some newer some rusty some flattened and they react differently and this is what I have noticed.
Some will jump all over from the 60's or 70's to the low 90's and no matter what you do you can't calm them down so that is also a clue.
Some will be a lot more stable in the dime range, almost a pretty steady 72-74 or so, maybe a bit higher, these are the ones that can fool you.
A few kinds will act the same but the numbers might be higher more into the 80's like a quarter.
When I first come into contact with a suspected high tone cap I try to picture it's position in the ground and make some short quick side to side swipes as I pull the coil back keeping the target in the middle.
When you get the edge of the coil over the cap or just a hair past the numbers should drop to iron and you will get that iron grunt.
Once in awhile the numbers don't drop that low, they could end up in the foil area like the mid 20's or so, but there usually will be a drop of some kind.
On a few very solid ones there might not be any drop at all, that would be in that 10% area, but sometimes if you turn and hit these from a 90 degree angle the numbers will change and this is also a clue.
Some will not drop, will not change when scanned from another angle and will stay pretty steady within a 2-3 number spread.
Nothing you can do about these, those you just have to dig but again they are in that last 5-10% range so it doesn't happen often and I am glad to do it if I can successfully eliminate most of the rest.
Coins will usually
never react this way, in my experience, unless you have some other metal in the vicinity masking or affecting them in some other way like the example I mentioned above.
A normal coin target should stay steady and stable from just about any angle, I have never seen one drop like a cap will yet, but weird things can happen out there so just listen to the tone closely too because coins sound a bit different to me than lots of trash does especially in 3H and 4H.
Also, as others have stated strange things happen out there in regards to chains and who knows what else so just stay on your toes and be alert and listen to the tones.
When in doubt....dig it.
As steve in so arizona said once, "We are out here to dig, not just swing".
This works well for me for targets at about the 6-7" or less depth area...deeper bottle cap targets
could act funny like beaver tail tabs that act like high tone coins at the 9-10" level or deeper.
Luckily, most of the trash in my soil is usually at that 6-7" or less area...mostly less.
I dug a huge amount of caps when I first started using this technique because I had very little confidence and didn't want to miss anything good.
After digging a few hundred that dropped and every one was a bottle cap I gained confidence big time and now I rarely dig any signal that acts this way unless there is something in the tone that triggers me to dig but that is rare nowadays.
I might miss something but without digging everything how am I to know, but it sure doesn't "feel" like I am missing anything good and I still dig a ton of good high tone targets so I am fine with my confidence level as it is right now when it comes to these things.
What I don't dig I don't worry about anymore and that is the most important thing to me because the "what ifs" used to drive me crazy...but with methods like these no more.
I also got very fast at this method with practice and now it takes very little time to make a dig/no dig decision regarding these things.
I recommended this to an F2 owner on another forum that was using the DD coil and was having the same problems and it worked so well for him he still thanks me every chance he gets so I assume this will work on every detector with a DD coil.
The ones with screens are going to be the quickest and most efficient when using this technique.