Bayonet

Hey guys Im just getting back into bow shooting and hunting after getting lazy and using a rifle for a few years. I dusted off my old hand me down bow and sold it to get a new one. I got a Bear Attack and was going by the old 5+ grains of assembled arrow per pound of draw. My arrows are coming out to about 392 grains and change. I stumbled on a chart that rattled me a bit when it said I need 420 grains at a min. I never worried about speed with my old bow because I prob could have thrown a spear faster and more accurately than it shot but the Attack shoots like a laser (to me at least. Do I need to ditch these arrows before the bow comes apart or should it be fine?

Thank you for any advice. I love shooting this thing and I don't want to ruin it or have to have an exploded limb removed from one of mine.