i put the lead core thru a spro swivel as mentioned befor and fold it back on itself. then i tie 2 nail knots with 12 pound mono on the loop created with the leadcore. have never had a problem doing it this way and it slides thru the guides just fine. the trick is to find a tool that ties the nail knot easily, i have a thin diameter piece of tubing that works well for the knot

I myself am cheap and go with a number 14 ? bb swivel if i can't find the small bb swivel I'll buy the regular swivel's with the clip and cut the clips out, I tie this to my leadcore (4" of lead taken out) then tie my mono to the other end and use another swivel with my fluro leader about 10' any time Ive gotten caught on bottom I've usally only lost my mono and leader not my leadcore, and the swivel's pass through the glides and levelwind with no problem, Of course I'm a Backwards Frenchman and am still learning so listen the Adrian he's the Pro LOL Take Care God Bless and Tight Lines LOL Donkey Dave From up North The Backwards Frenchman

Ive heard that if a fish runs after you have reeled him in past the barrel swivel it can take a guide off if it gets hung up on his run back out! Thats why I only use a barrel swivel at the last 8ft of my line. Im sure this has not happened or you would not set up this way. Have you heard of this happening?

the size 10 spro swivels are so small that the knot on the lead is thicker than them and it is not a problem and when fishing winni our drags are set usually about 1 lb. or less. it is pretty hard to tear stuff up with 1 lb of drag maybe if we were talking heavy duty stuff like big stripers or tuna it could be a problem but not our fish. more often the tag end on your knot will hang up rather than the swivel itself.

note: yes, all rods are different and have different action speeds and different sized guides and pick any other exception you want but on my cheapo (which i like the best) eagle claw light rods it is a non-issue.