Some pecking, I understand, is normal behavior and part of the dynamics of determining {forgive me} packing order. The wound sizes you describe are beyond that, however - certainly worse than anything I've experienced with my own flock of birds.
As
@3KillerBs stated above, medically significant pecking and feather pulling behaviors can come of bad integrations, sheer boredom, and confined spaces. It can also be indication of a protein deficient diet. Finally, it can be an indication of illness - but that's generally demonstrated by the whole flock picking on a single weakened bird, not the sort of widespread injury you describe.
WHERE ARE YOU??? I can't help you find a better feed if I don't know where in the nation you are. Temporarily, a can of tuna fish (in water) is high in good proteins, not too high in salt - though I wouldn't wan't to do it for an extended period. Same with a can of chicken. No sliced lunch meats. WAY too high in salt content.
You could scramble a few eggs and feed them back to them. 3 eggs per day for your flock. You can also poach chicken or pork (in my area, pork loin on special is routinely cheaper chan chicken, lb/lb) for them, feed them that.
Nuts/Seeds are high protein (though imbalanced) and also high fat - typically kept to small proportions (less than 10% of the daily diet by weight), but you could try some sunflower seeds (BOSS) - about 1/3# per day (total).
Cut the scratch, the cracked corn, and everything else that's diminishing your bird's protein. Chances are, this time of year, they aren't effectively foraging for bugs, either.
We'll help you locate better feed.