Keep at it.
I have made four Home Depot popular arrows, and I love my babies. All are at 508-524 grains, a mere 16 grains difference. Spine?, I do that by shooting sanding and flexing. They will group.
Have three more for the Zwickey's Blackdiamonds, ready to go... August 19th!
I broke 5 willow shoot arrows, as I have much to learn about harvesting correctly. Only one poplar arrow broke, a grain runoff at tip after about 25 shots through, over and to the side of a target, into the rocky soil of Arizona. I am very impressed with my creations.
If I had to do this all over, I would have got a test kit from 3 Rivers; my 3555 GTs are for my wife and I use one for rabbits. I am thankful for the spine adivce, prior post.
OK, stick with it. (I think newbies like me expect a much more seamless transition from rank novice to decently approachable apprentice in trad/primitive archery.)
To see your own arrows, with new fletching, self nocked, sticking into the focused area of the target, the center, is to be savored.
Floyd