Great reply from Flytyer!
Based solely on my experiences in upstate NY steelheading, I would also add that the philosophy of sinktips is to bring the classic dryline swing down into the water column deeper and deeper, not to provide a nymphing drift without split shots. Although I am not suggesting you are fishing this way, the fact is that most deep winter G/L steelheaders are drift fishing with fly gear as opposed to swinging a fly down in the column. My point is if the plan is to drift, you're better off with an indicator, floating line, weighted leader and weighted nymph. I personally don't fish that way out of preference but I am aware that it's very effective in the midwest and central states. I don't mean to imply anything by that clarification except that I worked in a fly shop in an area where everyone goes to Pulaski for steelhead and I have had a lot of experience outfitting people who did not understand this subtlety.
Personally, I fish the swing and move the fish to the fly verses the fly to the fish. Although this will not produce more fish in deep winter it kicks ass in late winter / spring as well as summer runs. To build tips that cast and swim well, I prefer a tapered sinktip like the old S/A shooting head tapers in type IV, III, II, etc. But even though the RIO sinktips are not tapered, they cast just fine as long as you taper down from a heavy butt to the tippet (acts as a taper itself). I prefer the old tapered shooting heads cut at 13' (leaving 17') for the casting but have to imagine I am getting deeper without the front taper on the swing. I own and use a wide variety of RIO lines and fish the tips in a broad range of densities. The wallets and color coding are great.
The theory is to blend a floating weight forward head back taper and belly with a sinking high-density belly and front taper. With this you can cast with a good loop transfer, mend, and swim the fly down in the water column. By swim, I mean hold the fly at some fraction of the current speed so that it dances in the current close enough to the fish to warrant a reaction - half the current speed being the general rule. It's really no different from swinging the fly on top except for the depth.
Therefore the ideal grain weight of the combined 'hybrid' head is the same grain weight (or thereabouts) of the original head. The ideal length is the same length. That way you don't need to change your casting stroke when you change tips - except for a more pronounced lift at the start and a more snappy pop off the anchor. But we all know that ain't gonna happen!
The reality is that when you need to get down you want more grains and we rarely get away without changing the stroke and timing to compensate. I usually switch to a snap-T with tips, or a snake roll.
With a snake roll and a floater, the start of the spiral can be small as long as the 'flip' is good. With a sinktip, the first spiral has to be big to pull the tip out and the flip is more subdued.
The snap-T, although you have to put some ummph to get the tip to snap, gets everything right where you need it and with a full sweep the dee loop is powerful enough to give you a solid cast with even a heavy tip.
Anyway, didn't mean to run off at the mouth - I love steelheading and this time of year I am thinking of steelhead and the pacific northwest all the time! :smokin:
Good luck with your tips!
