I love the way Black Widows recurves shoot, I prefer the way a longbow handles. I am not familiar with the SIW. My draw is 26.5", my arrows are all 27" bop. I shoot 1918s out of most of my low 50s to upper 50s bows, with slight point weight difference to accommodate the spine requirements. For wood shafts I use 45-50 tapered cedars with 145 Grizzlies for two bows and 55-60 tapered Surewoods with 160 grain Hills or Grizzlies for the rest. For my heavier bows I use 70 pound tapered cedars with 160 single bevel Hills, or the old Kodiak Grizzlies at I believe 170 grains. I do not worry about the foc with these arrows, it is apparently plenty to get pass throughs on whitetails in Iowa.