At your draw that sounds just about right.
I've been doing a lot of bare shaft tuning lately with my Damon Howatt Coronado 50@28 and I draw about 27" All bare shaft shots are shot at 20 yrds no paper tuning.
My 3555 are cut to 28.5 I have 100gr brass insert and it took a 200gr field point, but they fly like darts now.
My 5575 are cut to 31" also have 100gr brass insert and they also took a 200gr field point, but they to fly like darts.
Bare shafts don't lie and they can really reveal a lot about your setup