After the season closed last weekend I started playing with a new arrow combo(old 29.25 in gt trads 3355 2in footing 3/5in feathers 50grn insert 175 pnt, 28 grn nock end, always seemed to tune slightly stiff) tried some GT trads 1535s cut to 28.5 1in footing 11grn insert 225 pts, 3/4 feathers, 15grn nock end and tuned dead center bare shaft to 25 yrds. seems to work (but 1535s out of 51pound recurve?)
bow Dale Dye med point 3pc 48@26(I draw 27)12srtand ff sting with fuzzy sided Velcro as rest/strike plate
I'm always amazed how fast carbons stiffen up when you start cutting them back.
I have shot 1535 out of 50-55# longbows at28" and they worked great. Arrow spine is not an exact science your style and form play a big part in it. If they fly great bare shaft and with field points and broad heads. They rae tje roght shaft. If you are after a higher FOC or want to shoot heavey points you will probable have to shoot 3555s.
I use 15/35 from my 45# recurve. I have also used them from an old Bear Montana that is 50#. Mine are also cut to 28.5.
Bladepeek hit the nail on the head. Carbons respond quickly to reduction in length. I find it a challenge to find carbons that'll work for me out of my 42 pound longbow without loading up the weight up front. I too have shot the 1535 s out of 45 and 50 pound bows.
Another factor that makes sense is that you draw 27" (like me). That makes a lot more difference than people imagine in tuning arrows. You often have to go longer, or use a lighter spine than the calculator says.
I'm using 1535s on bows from 38# to 47#. Arrow length is 29". They fly great! I play with the upfront weight.