Yes, the vent rib will make a difference. I use to shot a plain barrel and still have some probs with the vent ribs. And yes, steel shoot different than lead did. You can' t shot as far and it just doesn' t kill like lead. Unless they are decoying in, they are harder to kill. Steel doesn' t have the knockdown power of lead. You can shoot a duck and he keeps flying, he may be dead just doesn' t know it yet.

There' s nothing wrong with your shooting, just the stuff you are forced to use these days..........