This is just my personal experiance, but i have a youth rossi .410 that throws a...well doesnt throw much of a pattern at all, but my high standard .410 with 26in. barrel throws a good patten.(my rossi is like 18") what im saying is a longer barrel throws better patterns further. just from my experience. also my dads 26in. barrel on his 12ga. pattern is worse than than his 28" barrel. so id say go with 28.(both of his guns are 870's) (best pump shotgun ever)