Weight will give you a rough idea, but i would still be wondering if i'ts gonna squib.
If the powder charge is missing or low, you will need an accurate scale to be able to detect +/- 4 or 5 grains.
If you only have 80 rds that are questionable, I would either pull the bullets & collect powder....or fire them slowly and make sure that you don't fire the next rd after a squib.
On your next batch, go slow and make sure there is powder in each case. I had the same problem after I got a Dillon 650. I didn't take the time to look into each case. I was trying to maintain 500-600 rds per hr. Now...I'm happy with 300 rds per hour and 100% reliable reloads.
Just my $0.02