I shoot the same arrows from all of my bows; CE Heritage 150's cut to 29" (I draw about 27 1/2")with 50 grain inserts and 145 grain points.  Normally, I shoot 5" Shield cuts with no issues at all.   Recently I fletched up some with 5 1/2" High Back Shields and now the arrow cork screws down range.  Would it be the additional height of the feather?  I felt it would stabilize the arrow better but definitely has a cork screw affect.  Anyone have similar issues?

I guess one should not try to fix it if it isn't broken, right?

If your arrow shaft spine, bop measurement and pt weight are good for your bow and your draw length you don't need fletching larger than 5".
5 1/2" fletching are not necessary.

sorry...double post

By adding weight to the rear of the arrow you are in essence stiffening the spine.

I switched from 5 1/5" high back shields to 4" parabolic and my arrows are flying just as well if not better.

Cork Screwing is usually 'bad release'/and or Nock point off.

Have you  checked your nock point?  

What is your nock point set at and do you nock above or below it?

If your new feathers are causing a problem you are borderline on spine....that extra on the fletching shouldn't be enough to matter.

Thanks for the input.

Terry:  Bad release is very possible.  Nock point is the same, as my arrows with 5" shoot great.  Change in spine might be the issue.

These are the same arrow shafts that I was using with 5" Shields but added the new 5 1/2" Shields.  Same everything but different fletchings.  My 5" fly like darts and the 5 1/2" corkscrew with every shot.

Strange for sure.

Maybe you are just seeing it better with the new feathers.  I love my high back 5 1/2s.  Really stabilize the arrow.

Doug....might be getting clearance issues...

If the 5's work...I'd go back to them.....the season is close here, not sure where you are at...but getting too close to fooling around...

Hope you figure it out......    

Why change something that works?

Could also be a brace height issue. If the 5" were just barely clearing the shelf, the 5 1/2" might be bouncing a bit.

Try shooting with the nock in different positions or cock feather in?.. I agree that if it's tuned, it shouldn't matter.. But if it's a clearance issue maybe that'll help?..

Can't see what you're seeing through an internet post, but it's possible it's optical allusion also. If the hen feathers are white or brighter than the cock feather it can give the allusion of cork screwing because you can see them so much better. Try shooting them in low light or shadows and see if it still looks the same! Now, if it's a pronounced cork screw it's not that. Also, did you actually check your nock height, or are you assuming it didn't move???

I'm in agreement that it's a clearance issue.  Adjusting nock height or brace height or both will probably clear it right up.  Assuming your arrows aren't borderline on spine.

Jake