...Why do most tapered shock leaders you see end in 15lb line ?
From my carp and pike fishing experience you usually want the weakest point at the hook and lead end not 13meters up your line .
My reel is spooled with 20 lb line and the hook lengths or snoods as they are called are 30lb onto 60lb rig body line ,even if I had 15 lb main line I would still not want my weak point to be a knotted bit of 15 lb line.
Traditionally, 15lb line was used as the main b/s line for beach-casting, being a compromise between the maximum you were likely to need fishing from the shore together with the (then) smallest diameter to enble distance casting - at one time 15lb was specified as the main line to use in tournament casting. Any thicker and the aerodynamics were messed-up and distance decreased.
This has changed in more recent years with changes to line strength v. diameter and totally goes out of the window when braid is used!
The main problem with the 15lb line was on casting with crack-offs being a danger using 4-8oz leads - leading to the use of 'shock-leaders' to give a higher b/s end to the line ensuring less likelihood of breakage when the maximum strain is applied at the start of the cast accelerating the weight from a dead start. The guideline iirc was 10lb of b/s for each ounce of weight - so for a 6oz weight you'd need a leader of minimum 60lb b/s.
Length of Shock-leader was determined by the length of rod used - typically Beachcasters were 12ft - so you'd have 3m hanging from the rod-tip to the weight, 3.5m from tip to reel, then about 8-10 wraps around the spool - say about another metre or so depending on spool size - giving a total leader length of 8m minimum.
With a straight tapered leader this could be increased to give a bit of insurance to make sure that the casting strain wasn't subjected onto the 15lb mono.
The rig line (when not clipped-up) becomes part of the shock-leader hence it's high b/s. The snoods (not being heavily loaded) can be a breaking strain more applicable to the end-fishing needs.
This all depends on the type of fishing you are doing, over what ground, and from where or what. If all you're doing is flicking an ounce or so off the rocks, or dropping it down from a pier or boat, then you probably don't need to go the 'Tournament Beach Casting' route with a shock-leader!
Hope that makes sense - Tight Lines:thumbs:
