If the arrows rattle when you shoot and are sliding down after a few shots, then it’s not your foam in the hood, it’s your gripper. Sounds like your gripper is the wrong size.

If your shooting carbon, many of the grippers have to be switched out to the smaller size. Most standard gripper are for either woodies or larger aluminium shafts.

Troy

From reading your post, it sounds like maybe you are not pushing your arrows into the foam. No need to drill.

Take the broadheads you are planning to hunt with and strategically orient them to fit in the hood. Then just push them up as far as they will go. Done.

Then put your field point arrows back in and push them into the holes in the foam that your broadheads made. I think that will solve your problems.