Most Ilf limbs # listed is what they are at their lowest setting with limb bolts backed out. Most will gain 3-5# when screwed down as far as they will go, and backed out at least 1/2 turn which is suggested as the bare minimum. Ilf rigs, especially the metal risers are the easiest to tune bows I have ever worked with,and with a plunger button and a flipper type rest, can shoot a wide variety of shafts/spines. One evening this past summer, I shot a Titan 17" riser, medium limbs, #50, 60", with 12 different arrows/spines at 25 yds, and got perfect flight with them all, with just a turn in or out, or two, on the plunger button.One of my buddies shooting of the shelf could not believe it, as he has had a heck of a time tuning. It took this for him to start shooitng off a rest, and his shooting has gotten 3x better, as I believe, shooting off the shelf magnifies any human errror. I dont ever believe I will own anothe bow that is not cut past center, for tuning purposes alone.