Flight Shooting Fail

Damn...
The grass in the secret flight shooting field has shot up over the last two weeks and was too long. It didn't stop us trying, but it took an age to find 'em and we didn't want to risk shooting them again.
They were shot from a 100# warm up bow, not the 120#.
It's impossible to draw definitive conclusions from such sparse data, but there are some tentative conclusions. I shot the arrow with the odd flights from a short draw and it was predictably short and can be ignored.
Of the other 4 arrows two were very close to each other, one was about 6 yards further and one was about 6 yards short. I noted that the flight was fairly clean  but there was some tail waggle
The furthest was the weakest spine (70-75#)
The shortest wasn't the strongest spine but was 80 -85#
I can tentatively surmise that weaker spine isn't significantly worse and that spine isn't overly critical as there was no vast difference.
I'll be measuring up some other flight arrows which I know have performed fairly well from the bow in question, and see if I can improve on those.
The downer is that we have no where to shoot for distance unless the field gets cut for hay.

A friend is giving me some pieces of parchment so I can experiment with that for fletchings. It's good to share materials, I sent some horn to one of the UK guys on Primitive Archer.
There's a good community spirit, the mini bow (24" long) I made from the broken Yew heartwood primitive got to the Marshall Primitive meet in the USA and apparently was quite impressive. The mini bows shot well, one of the guys sent some pics reckons they would get you meat if the need arose (or presumably stop a zombie when the apocalypse comes).