|A couple of paragraphs from Chapter one - History of Shooting heads - the book I never finished.|
We've been making heavy, dense shooting heads for decades...
"Despite the standard lead-core line's ability to dredge bottom during normal flows, it couldn't get the job done when the rivers were nearly at flood stage, so Bill Schaadt developed a new idea. Taking a length of heavy Dacron fishing line, he inserted lead fuse wire to make a lead-core shooting head of considerable density. The result became known as "The Cable." It can be made from 2-, 3-, or 4-ampere fuse wire, weighing anywhere from 550 to 1200 grains, capable of sinking a fly so deep it’ll catch fish with headlights. Of course these lines cast just like their name implied, and needless to say, you didn't aerialize the false cast. Water-hauling (some times referred to as water-loading) was the only safe approach to casting the cable."
"A system can always be improved, and Frank Bertaina of Santa Rosa, California, added a new twist to Bill's Cable. Frank removed 22 feet of the 1-ampere fuse wire from a 30-foot length of standard lead trolling line and replaced it with 2-, 3-, or 4-ampere fuse wire, creating a tapered lead core shooting head. These cables were used for years to overcome extreme conditions, until modern, nearly as fast sinking but more easily castable versions were manufactured by leading fly line companies. Extreme water conditions were the prime factor that required pulling a Cable from your line wallet, because they were, indeed, "extreme" lines. I still have a few of those that I made more than 25 years ago, and have occasionally used them when the flood gates burst or when plying the bowels of bluewater. And, it's interesting to note, that the Cable handles much better when cast by modern, carbon fiber rods."
Personally, I think a 30-foot length of T-14 is more than adequate for fishing depths to 30 or 40 feet provided the currents are not too strong and you follow the advice/tactics GES described.