Someone mentioned using rope instead of weight tubes to make your carbon arrows heavier.My arrows are 275 grain and 5/16 thick.My main question is how many grains per inch nylon rope end up being.

Are you sure it was rope? Not weed wacker line?  
I do not know weight of either.

Ya I think so.What is wacker line?

my suggestion is to forego internal carbon tube weights and load the front end up.  doing so will rarely, if ever, make any dramatic spine change.  and having added weight up front increases foc and directional arrow stability.  add weight easiest via steel screw-in adapters.

Wacker Line


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X2 on the steel adapters that Mr. Rob mentioned.  High FOC.

That's the direction I'm going too. I just left a post on my local bulletin board service for old Easton 2216 aluminum shafts to foot my GT Trads with (and increase my FOC) and got a hit in less than a 1/2 hour.

Yep, Old glue on green razorheads with 100 grain adapters.  You have to use a drimmel tool to get the bleeders to fit.  Old Fred knew how to make a broadhead