i have about a dozen Scheels store brand Rogue arrows, they are GT Hunter arrows that are store branded. I had these until I got more serious and bought "real" arrows, but now I feel that these arrows just sitting is a waste and I want to turn them into decent arrows. 29.5 inch arrow 340 spine 30 inch 65 pound draw would 50gr insert with 100 grain head be too much for that shaft? I already has the inserts could just glue them in and refletch and have some cheap arrows that could get the job done.
You might be ok and get that to tune, then again you might be a little weak. If you cut them back an inch you will be fine with the extra weight up front for sure
If you have a 30 inch draw, 28.5 might be too short an arrow but maybe not. You could always try starting out with adding 20 to 30 grains additional weight and see how it goes. Move up incrementally and see if it gets better or worse.