One way to check fishtailing would be to shoot through several sheets of paper spaced a couple feet apart. 6-8-10-12 feet or so. Then look at the tears. That would give a definite sign of anything strange going on during arrow flight. Or space them out further if you have the chance, 5-10-15 yards......Tears might not be as predominant as it looks without the paper, but it should show any fishtail. Guessing the paper might straighten the arrow out some as it flies through....
2006 Rytera Bullet X 60#---2008 Moab 70#
2008/12 Firecat 60#--- 2010 Warthog 70#
2010/2012 Alien X 65# 2011 Onzas 60 & 70#
2009 Warthog 70#---2009 Firehawk 70#
2010 Strother SR-71 65# & 2012 Strother Rush 65#
I hunt, therefore I eat. lol