I have a Widow PSA 2, 52#, 56". I tried the Gold Tip 55-75, 30", 125 gr up front, 3-5" left wing helical. Can't believe how perfect these fly. No fishtailing, or porpoising. I put some Magnus 2 bl Stingers (100 gr)on just to see how they fly, and again...lazer like flight. I would have thought these 55-75 shafts would be way overspined. I'm pleased as all heck, but it just doesn't make sense? Or does it?

That should be the spine at 28" and your arrows are 30" so that should make the spine slightly weaker.  And some bows seem to be more tolerant on spine of arrows.  I have a bow that is 54# at 27" and with a 150 gn grizzly, 2020's fly well which are way over spined.  And you must have a good release/form.  IMHO.

Every bow is different, riser cut, string material, silencer type and placement. Your release will also impact spine needed.

All of my Widows like a HEAVY spine.

If your arrows fly perfectly, you're not overspined. What more can you ask?

A lot of that has to do with the degree of center cut.

I hear them widows are so fast you have to have a really stiff arrow to keep them from exploding at release.    

Yes, I concur.  They seem too stiff on paper, but proof in shooting them.  If it ain't broke, don't fix it.

My Hoyt GM2 likes GT 55/75 with a 125 tip on it but I cant shoot a 100 gr broadhead on it.

clear, I don't know nuthin 'bout them new-fangled materials, but with wood that means your spine isn't right. Broadheads are the ultimate test of correct spine.

hockey7:
Your widow is cut 3/16" past center at the strike plate, that requires that you increase the spine. I normally increase spine 15-20# over bow weight, minimum. then add or subtract for arrow length over or under 28".
Bob

Hey Don my high tech toy shoots a 125 gr broadhead like a lazer beam(thats why I shoot a high tech bow so I can talk high tech I just dont understand it HAHAHA!!!).I just cant get a 100 grain head to fly on target(hits left) but my 125 stingers are dead on!!!