For decades I have spent the bulk of my hunting time in older-use sites that abound in nails and other iron, and non-iron, trash. Some of the most challenging for any make or model detector and any search coil [size=small](detector brand or aftermarket)[/size] are most of the old Railroad townsites,
especially if they were a long-term, active, bustling RR spot.
For 32 years+ I have made it a point to have one of the best general-purpose detector models on hand for dealing with a dense iron nail environment. Those would be one of several of my favorite Tesoro models, most often equipped with a 7" Concentric coil .. until they introduced their 6" Concentric.

Not only are my favorite Tesoro's equipped with a 6" diameter Concentric coil light, balanced, and highly efficient in their abilities to weed some keepers out of dense iron debris, but they have been/are the models by which I compare all other detectors, regardless of their cost.
I have had
passable performance on my
Nail Board Performance Test with the White's MXT Pro w/6½" Concentric coil, or the Teknetics Omega 8000 w/5" DD coil. Currently I have
passable performance from my Teknetics T2 'Classic' w/5" DD coil,
if I am cautious about coil sweep speed so as not to sweep too quickly. That said, the Nokta FORS CoRe w/
'OOR' coil and Makro Racer w/
'OOR' coil both out-perform any of these mentioned models in a dense iron infested site.
Back about '01Tesoro brought out their 8X9 coil, and since it wasn't a pronounced elliptical shape I started using the term
'OOR' because it was just kind of
'Out-Of-Round' compared with their stock 8" coil. Still, I preferred to use the smaller 7" and now the current 6" round Concentric coils on my Tesoro's, then along came the Nokta FORS CoRe and Makro Racer.
Since I almost always use smaller-than-stock coils most of the time, their little 4.7X5.2 Double-D was a perfect size, and provided ample in-the-field performance. In discussions and in print, I quickly started using my
'OOR' reference for it, too, because it's just a slightly 'Out-Of-Round' shaped coil. Besides, it is easier and shorter than saying it is a "four-point-seven by five-point-two."

Besides, with the exceptional performance I get with that coil mounted to an excellent circuitry design, it kind of deserves a nifty handle to make sure attention is called to it.
The Makro Racer w/
'OOR' have been providing me with above average performance in dense iron challenged sites now for eight months and this combination has easily out-performed all other modern, digitally-designed detectors out there. This combination is a little more forgiving if you errantly sweep a little faster than the MXT Pro or T2 or F19 and most other makes and models, with the only exception I have found being one of my favorite Tesoro models with a 6" Concentric coil. The Racer/
'OOR' combo come closer to their performance than any other detector I have used, and believe me, that says a lot about the performance.
Right now I am just west of you a bit in Gilliam County
(Arlington specifically) and would be glad to meet up with you this month and let you check out the performance of the Makro Racer and its excellent smaller coil. I am not a fan of most after-market search coils and doubt that anyone could come along that would impress me like the
'OOR' coil does. It is hunting season, and I have been checking rent rates over near Ontario as I plan to move soon, but I am sure I can meet up with you and let you borrow one for a few days to give it a try. Just shoot me an e-mail or give me a call.
Trust me, you need to put it to the test against any of the models you have listed in your 'signature' using comparable smaller coils, and make my
NBPT the challenge they face. Note that the Racer and
'OOR' are part of my current detector arsenal, and it is for a very good reason ... the combination 'feels' good, 'balances okay, and provides me the excellent performance I want and need in highly trashy site encounters.
Monte