Need advise

[Producer]

I like Gold Tip traditionals for my 57lb longbow. My arrows are cut to 30" as my draw in 29". I have 160+ Ziwicky heads with aluminum inserts and to me, the arrow flight is great. I know that cutting two inches off of carbons makes them stiffen up quite a bit. My question is, if I added say 100 grain brass inserts and used the 400's in my 47lb S-K would or rather should the arrow flight be good? I have the arrows and I am thinking of ordering the inserts thinking it would be OK but I need advise from someone who has more experience on the subject.

[Bladepeek]

I'm shooting 3555s out of my 46# RER LX and a Bear AuSable 53# and get the same flight from both.

They are 29.5" long with a 9" wrap and 5" low-profile parabolic fletch. If I change to 5 1/2" shield cut fletch, I need to add another 50 gr up front. I have some 400 spine 5575s that fly exactly the same as the 3555s, but they are 30.5" with 300 gr up front.

I'm pretty sure you can do some playing around with insert weight and fletching and get a solid match for your S-K. It may take a bit of playing around to do it, though.

[Producer]

I have 5" shield cuts on and I am thinking from what you said that 100 grains added will not be enough. I think the std insert is 19 Grains so I would e adding 81 grains. People say your arrow should be cut to one inch over your draw but they don't talk much about what effect that it has on stiffness. They don't fly horribly now so my thinging was going with the brass inserts instead of buying new arrows. I thank you for your advise.

[kevsuperg]

GT standard insert weighs about 12gr. You can use the threaded weight system with them.  Remove the nock and insert the weight from the rear to the insert with the special long " insert tool ". You could removed the insert, add the weight and reinstall the insert ( that's what I do) .
 I think the 1" past your riser comes from wood arrows and or compounds.( looking for speed )
 The carbons are sensitive to cutting,  1/8 " can really make a difference when youre close to the correct spine.
 I draw 27" on my 50#@28 bows. GT 3355 3x6 shield, 30.5 " 200 gr up front, 175 fp,standard alum. Insert, 10grs insert weight .
 I like the extra length, helps me get a close to 500 gr arrow