Just recently got some beman mfx classics 340s and spined according to OL , This was done outside on a sunny day, gotem to 29.5 with 100 grn insert and 125 point. Fletched the other 9 with the same colors two yellow and one red barred.
Ready to shoot, go to an indoor range the next day and fling away , to my amazement and disbelief they seem to be tail waggin and spiraling 2 inches or so , so I experiment for no kidding, three hours everything tested, finally diheartened I cut them another 1/4 inch and reset(had the inserts in with high tensile hot glue highly recommeded). Yep still saw the tail waggin, so now I think I have really messed up and decide to give it a break, 3 hours later and after conversations with some of our Trad gang members decide to try them one more time, go out side to my girlfriends and shoot them,,perfect flight,,yehaw,,,Must a been my release,,,, Back at that same shop today and yep tail waggin and spiraling , but no it is the lighting in the shop giving the appearance of tail waggin with the two bright yellows showing and the red not...common sense that evaded me
So in short check your flight in a bright area, and do not doubt OLs method!!!