Factory measurements on bottling bucket

Just started batch priming, did my first batch today. Has anyone ever had a bottling bucket where the gallon marks printed on the side are off? I used masking tape to measure in 1 quart increments and found that the factory marks were about 1 quart less than a gallon.

I have done a mod to my bucket with a PVC drop tube, but I wouldn't think that small of a displacement would would make that big a difference.

Thanks for any opinions.

I never checked mine but it seems to agree with the marks that I made on my Better Bottle. That is assuming that the measuring cup that I used to make those marks was accurate!?