Nitesite
I agree with you on the timing after rains. I belong to a private club and am allowed to mine the berms which have never been reclaimed. After my very first time (just curiosity on my part), the interim range mangler got the sh8hot idea that he would bring in some equipment and mine it himself. I got the idea that they found him to be over-exhuberant and inept, so they canned his worfless butt, yet they still allow me to mine.
After my initial proof-of-concept expedition with a garden sifter, I made a small (industrial grade) screed (10" x 15") out of a piece of 1/4 inch machine screen with 3 sides of light angle iron which I welded to it. It was strong enough to hold anything I pick out of the berm yet light enough to not bust my back. In less than an hour I can collect a 5 gallon bucket, which has about 150 Lbs of smelt and maybe 20 Lbs of jackets. They think I am nuts for wasting my time doing this, as I lug my sh8 out to the truck/car. They shoot their fancy-dan store-bought jacketed or cast boolits. I'm wondering why they bother to reload. But I can load a box of 45 for well under $5. However, I'm retired while they still work. I enjoy all the time I spend in the garage and down in my man-cave pulling the handle on my Dillon.
Maybe they enjoy their time away from their wife, too.
I DO like your sand flea bucket and will make one out of reinforced steel screen similar to my screed which will greatly increase my collection speed.
The fellas in my club have been watching me do it and some are quite envious of what I do and how efficiently I collect the lead (none of them cast now; some used to) but with your "flea bucket" idea, it's gonna be a new dawn rising ! I LOVE IT !
And as at your venue, our berms are clay but pistol rounds don't penetrate very deep so after rain/sun, there's lots of stuff on the surface.
I think I'll make a larger bucket and a pusher/rake/broom so I can stand above and "encourage" the loose stuff to roll down the slope into my bucket (like 18" long, 4 or 5" wide, and 6" deep), shake out the dirt and dump.
My only problem is having to haul my collection back to the line, lift into the trunk. However, today, they let me drive my car out and I didn't have to drag very far. Nice thing about being in good with the club officers. I also inquired about mining bird shot from the trap and skeet fields but the proximity of the woods and swamp are not conducive to doing anything like that. I offered to buy the machine to separate the shot from the dirt and then the club could sell the remnants to local reloaders and pad the club treasury. But when we walked out to the shot drop area, it just isn't all that feasible. Looks like we're stuck with mining the pistol and rifle berms. However, the rifle slugs in long range berm go deeper than the pistol boolits so that pretty well limits us to one of the 3 ranges. However, 50 or 60 years of pistol shooting should have deposited plenty of lead for us to reclaim.
Like you, I filled my bucket with water but I let it let soak overnite. Dumped and hosed off the dirt, let dry in the sun, leaving good reclaim. Smelt and on to casting.
After mining all this lead, I decided I might need something better than my LEE 10 Lb pot so I picked up a MAGMA BULLET MASTER and a STAR SIZER/LUBER with auto-feed. I might just build a motor drive for it. A couple people asked me during the shoot today if I sell boolits. I told them that I don't. YET.... I explained that while I have a number of desireable moulds for my MAGMA (38-158 SWC, 45-185 SWC, 45-200 SWC), I don't have the 2 heavy 45 moulds (230 and 255 grain) I'd really like to have. Somewhere along the line I might find them, tho.
Oh, the berms around here aren't sand. They're hard clay just like yours!
After a torrential rain, and following several sunny days to dry things up, the berms I see are literally coated with bullets on the exterior surface, with most of them on the lower third like they got washed downhill by the rain.
This sand flea rake cuts about half an inch of powdered clay and all those nice spent bullets in one uphill drag. This trial run worked great on clay berms. Give it a try!