2317's would be way too stiff for a 50 pounder. If you can grab a couple of 2016's to try out, I think you'll see a dramatic improvement. With a 125 gn point, 29" 2016's - I'm assuming you draw 28", of course - will weigh around 475 grains. That's according to the arrow weight calculator at Jackson's site.

If you haven't got Jackson's bookmarked, you're doing yourself a disservice. Lots of great tools and info there. http://www.bowjackson.com

edit:

Here's another site you might find handy for chasing down a good arrow spine. http://www.arrowsbykelly.com/Spine_Charts.html