Nope, it's the Ace.
I don't mean to be harsh, but few detectors will be able to deal with that kind of situation. My Minelab Sovereign would have to just sit in the van if it's all I had with me.
I have real old Tesoros that don't make a lot of noise around a lot of iron and the Compasses don't do that either.
In fact, I installed a shunt alongside a 5-5000 ohm pot on my GB on my old Compass RM7 just for fun and I can lay a piece of 6 inch by 6 inch by 1/2" steel plate right on the ground and cancel it completely. Then I can lay a nickel right on top of it or beside it or 6 inches from it, and pick up the nickel very clearly. With my Compass XP Pro or my Compass Scanner R&C I can cancel a steel washer the diameter of a donut and when I put a nickel or other coin right in the middle of it it will sound off on the nickel but not on the washer. I can do the same thing wth a Tesoro Silver Saber, Golden Sabre, Compadre, or Silver uMax or almost any other Tesoro too. An Ace 250 will not do that. It can't because it has a delayed response and can't keep up with that much target change, nor that fast.. A.H. Pro invented discrimination (1972). Tesoro invented "Control Phase Response" discrimination, very rare and very exclusive. Fisher invented automatic ground balance. Compass invented auto-retune, DD coils, etc.
The old 1970's A.H Pros could do the above washer test easily. Those were really good discriminators too, some of the best. A.H. Electronics INVENTED discrimination (patent #US 4263553). An AH Pro Quintron or Phantom (the first ground cancel discriminators), also patent #US4263553, could do it too, not just their "Super Pro", Backpacker, etc models. A White's Classic can do a fair job of it and so can a Prism, but not as well as the new Tesoros or the old Tesoros, AH Pro's, or Compasses. An Ace 100, 200, or 300 can't do it and neither can an Explorer. The old Tesoros were a bit better than the new ones at canceling iron. Like one old man I used to know who was a dealer, said, "they don't make 'em any better, they just make 'em different". BTW, Westinghouse Electric invented multi-frequency detectors back in 1972, not Minelab.
I often use a 3 inch coil on my favorite detector, but I also use a 6 inch, and it's the detector that really makes the difference, not the small coil. Yes, a small coil helps, but mostly they are best used to find smaller items like earrings, not to cherry pick any better, regardless of what people might think. I know because I used to open them up and repair the things, and they are a real mess to deal with too. The coil windings between a 3" and a 6" coil are nearly the same diameter inside the casing. Compasses though have "tuned" coils, meaning that they have a circuitboad inside the coil that balances the signal instead of using a balon capacitor or coil to control it. Nautiluses have this too, but they are set up in a different way.
Go online dude. Get a cheap Silver Saber or Compadre and enjoy the hobby more- without all the falsing. I still have a 1983 Silver Saber uMax and it has NEVER falsed, not even once, even on the nastiest of salt/magnetite beaches. It won't even false if I run it over a piece of 6'X6' solid steel. Neither will my Golden Saber. And they are both 24 years old. Tesoros are silver MAGNETS, perfect cherry pickers, and probably about the best discriminators you can buy new or old. I have found more silver rings and coins with my old Silver Saber than with all my current 23 detectors and all my old ones combined, and it only weighs 2 1/2 pounds. I've found the most gold with my Compasses though, with a cz-70 coming in just under the Compasses..
You can buy a used Silver
Saber for as little as $50 on eBay or Craig's List and they are real sweethearts.
One last little secret: The new low cost Tesoros are not a whole lot different in their circuitry than the ones from 20-25 years ago. That's why they work so well in a lot of iron.
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