I gave breakfree a try once. I used it to clean and protect the bore of my enfield after shooting noncorrosive remington ammo. 2 days later I had rust in the bore.
I never tested Break Free on a nail but i did test it for weeks on end in driveing rain and snow while hunting on the Alaskan Peninsula. I also tested it in the temporate rain foreston the coastal islands of Alaska. It worked very well to keep the rust off my firearms and other gear. In fact, itworked so well, it was hard to keep it on the shelf, as it sold very well.
Another thing, when hunting in the mountains or in the winter, the cold weather has no affect on Break Free. Even snowmobileing in below zero weather, my guns keep on working well. It's great than you canuse the same lube year around.
There are so many products made today that are better than WD40, i don't even buy it anymore.
Robert