A few months ago I posted about how I had some chundoo shafts purchased about 20 yrs ago, had weighed and sealed them back then, but didn't remember what spine they were supposed to be. I took the three closest in weight and made up 28" arrows with 125gr tips to try.
I am shooting a 47# recurve at 26" draw with ff string and 2016s 28.5" with 145gr tips shoot bullet holes in paper so had an idea of where I should be - but not what I had. One shot just like the 2016s but the other two were hitting nock right (I shoot left) at my 5yd form butt.
I have since built a simple spine tester using a dial caliper to measure deflection. The one that shot ok measured 57# and the other two were 49# and 45#. I cut an inch off the 49# and it flew much better as did another at 48# also cut to 27". For reference I measured a 2016 across 26" and then found an old post here of what it should be at 26" and was within .005" which verified the tester and my technique.
I have six more shafts in two weight groups that measured 51# to 54#. May make a few flu flus to try. When it's time to get a matched set it's looking like I will be able to go with 50-55 at 27" or 55-60 at 28". Still got time to decide on wood type and overall weight. Boy, it's fun playing with woodies.
Good to hear you're enjoying it.'Been thinking of rigging up a dial caliper setup for a while myself, it's encouraging to know it's working out accurately for you.
Joe,
It was your post inquiring about the Ace Spine Tester that got me looking at designs on the web. There are all kinds from simple to contraptions that look like furniture. I copied the simplest one I saw using a caliper. Didn't even put a base on it - just throw it in the vice and level it. It's slow because the contact point of the caliper is so small but can't beat the cost - $3 for the clamp. It works for low volume measuring.
(http://i.imgur.com/GhFd5lS.jpg)