I have a Pro Kennex Ki5 PSE that came in at 27 1/4 - I actually preferred the extra length. If you have two and one is longer with the same strings and tension (or you measure both without strings), then you could cut the longer one or just choke up a little on it.
As others mentioned, check the buttcap and pallets if you can. It is possible that the pallets are out a little further from the hairpin.
4 x IG Prestige MP, 70 cm, 376 grams, 386 SW, ALU Power @50