How many did you put in the turkey plucker at a time? It probably would work better with 3-4 in there to bounce off each other. Also, a bad pluck can be caused by a poor scald. I like to use 150F water and dip-and-swish until I can pull a wing feather easily.
If you aren't set on perfect roasting carcasses, you can also cut up the sides of the cavity when you're gutting them, so that a larger hand will fit. Good poultry shears work well for doing this without snagging/piercing intestines. Just hold the bird a bit sideways so that the guts hang down from the side a bit and cut a slit up between the keel and the backbone, if you look at one you've already processed you can see exactly where you'd want to cut.
Good job!
If you aren't set on perfect roasting carcasses, you can also cut up the sides of the cavity when you're gutting them, so that a larger hand will fit. Good poultry shears work well for doing this without snagging/piercing intestines. Just hold the bird a bit sideways so that the guts hang down from the side a bit and cut a slit up between the keel and the backbone, if you look at one you've already processed you can see exactly where you'd want to cut.
Good job!