I was wondering if there is a way to calculate the Skagit/Scandi grain window for single hand fly rods given the CCS ERN measurements. If not, how do you guys estimate the low and high boundaries? It's not really practical to try dozens of different shooting heads with each and every build. For spey/switch blanks this is not a problem usually, as the grain window info is provided by the manufacturer, but more people start to use their single handers with some type of shooting head, so this is where I need your help.

Without knowing whether the single-hand fly rod's user will be a double-haul caster or a wave the wand caster the CCS ERN rod measurements are of little use.

There are fly fishing books published for over 30 years explaining shooting head systems, their use and how to build them. Nothing new to salmon and steelhead anglers everywhere.
Much cheaper to build than buy.

Hmm, maybe I didn't formulate my question correctly. If I am not mistaken, the ERN should help in choosing the right line for the rod. So, if, for example, my 8wt SH rod's ERN is 9.75, it would make sense to try a 9wt line for overhead casting. Right? I understand that different casters with different ability levels and different casting techniques fishing different waters might end up with different lines on that same rod, but that is given and beyond the scope of the question here.

My question is how to estimate the minimum and maximum shooting head weight in grains for the SH rod above if I want to use it for spey casting.

That would be correct if you are holding roughly 30 feet of line beyond the tip. Less or more might require you to adjust to something like ELN = ERN+1 or ELN = ERN-1, or whatever. You could also convert the standard AFTMA line weight to grains and compare that against your shooting head. Weight is weight.

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Thanks Tom! Good point about comparing the AFTMA standard weights. Need to try that.

I was actually thinking along the same lines. Weight is weight, whether it's regular fly lines or shooting heads, doesn't matter. I was just wondering if there is any adjustment due to the differences in overhead vs spey casting styles.

There can be. The easiest way to factor what you need is to take a rod you have now, which you feel is dialed in for the head and casting style you use, and run the ERN for it. See where that puts you and then use whatever factor you need to link to its ERN and then use that for every other rod you find the ERN for. Once you have a baseline to go by, the rest is easy.


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