for carbon hunting arrows, i never liked using shaft tube inserts. it just made more sense, and better arrow flight, and the promise of better penetration, to load the front end up.
this kills two birds at once by both upping the arrow gpp, and effectively increasing the foc (as a by-product of the front end weight).
i always use glue-on broadheads and vary the adapter weights to suit the arrow's final weight. i've also used heavy brass inserts, too.
carbon shafts have high *dynamic* spine ratings. this is clearly evident by the wide static spine range all carbons sport ... i.e. - "35-55", "55-75", etc. you will NOT see that with woodies! there is no, or very little need, to worry over shaft/arrow spine with carbons.
i use beman 500 bowhunters @ 29" with 350 grains up front for a 585 grain arrow out of longbows that range in holding weights of 52# down to 44#. for the techies, that equates to a 29% foc arrow, though i really don't care much about foc or efoc or lmnop. :D
heavy arrows may be a tad to a lot slower at yer typical game shooting distances, but they're typically more stable, more forgiving, more quieter, and have more penetration than lighter gpp arrows. ymmv.
so, load up yer hunting arrow's front end to yer heart's content. :cool: