mr green
I shoot Schafer Slivertip receve bow 55# @ 28" . My arrows are also 250 heritage 29.5" .  I shoot a 200 grain point and 50 brass. They group just slitly weak with bare shaft . With fleshing . They will be perfect . Total arrow weight 625 grains and FOC of 19.5 %.  Broadhead is journeymen 145  with 75 grain steel insert. now known as eclipse broadhead. Just  try adding point weight .

Mr Green, thats great news. The spine calc can be really useful, especially when making changes in arrow specs (once you have a baseline established as you do now). I like to toy around with it when I work a new bow or new arrow material. Anyhow, I'm glad you got it sorted! Happy shooting!

So, here's an update.-
Despite all the great help from the guys who pitched in here, I still screwed up on the 3R Spine Calculator. When I entered my info I failed to include Center Cut measurements, Doh!  With this included, it seems my best choice is a 125gr head with a 50gr insert. I'm happy to keep the 125 grain head since it gives me so many choices for broadheads. Just to be sure I have a couple of bare shafts coming from Lancaster cut to my length. Once I'm done tuning with them I'll probably put a dozen arrows and a new string on my Christmas list.

175 still isn't a slouch for tip weight. While a ways away from EFOC, UFOC, or whatever, generations have been slaying with just 125 out front. Plus, I've botched the calc a few times too, haha. Its all a part of it. Get set and happy with one set up, nail the form and stuff down, then you can always re-attack and work a new set up down the road knowing you have a proven design still in the quiver if you get turned around.

what I do is shoot bareshafts to see how the arrow flies, that will tell you the exactly what is going on, I'm no expert as I have only been shooting for two years now, but if you get masters of the barebow vol.2 it has a segment on bareshaft tuning and most of the experts will say that is the best way to tune an arrow to a traditional bow and from what I have seen I will agree.  I have played with the calculator on 3 rivers and it will get you in the ball park but nothing will get you on the money like bare shaft tuning.

mrgreen- you must read this about bareshaft tuning- it will explain the entire process.  It is actually fairly easy once you understand the dynamics.  It is VERY different than typical modern compound thinking however.  For example:  My Heritage 350s - a 1/4" difference in shaft length can change an arrow from not so good to perfectly tuned.  Just moving from a spine .300 to .320 can change a lot.  Then you have FOC, gpp, brace height, etc.  There really are not many variables- but you do NEED TO KNOW how they work out together.  Once you understand it you will be able to answer your own question. AND best, you will find yourself enjoying watching a perfect arrow fly.    

 http://www.acsbows.com/sitebuildercontent/sitebuilderfiles/tuninglongbowsandrecurves.pdf