point weight change and wood arrow spine

[Jim Wright]

I was wondering what others experience has been concerning this subject. For example, say an arrow weighing 550 grs. spined 50-55#, 30"s long with a 125 gr. point flies well from a 53# @29" Hill style longbow. How much heavier spine would be called for to shoot a 175 gr. or a 225 gr. point keeping total weight the same?
 Common wisdom seems to be a 5 pound spine range change for every 25 grs. in point weight but as I experiment I am beginning to doubt it. Any help is appreciated.

[SlowBowinMO]

I have found jumping up a spine range for only 25 grains quite excessive.  I can usually jump from 125 to 160 with nothing more than a 1/4" arrow trim, if that.  If you are well tuned at 125, a jump of only one or perhaps two spine groups at the most should let you shoot points well over 200 grains.

Don't forget something as simple as a matchstick under your side plate can reduce your need for spine dramatically.  In fact if you build out your side plate now you may find the arrows you already have will tune just fine.

[Jack Denbow]

My experience has been with all else being equal increasing the weight up front by 50 grains would require a spine increase of 5 pounds, 100 grain increase, would require a 10 pound spine increase. I think it would be hard to keep the total weight the same while increasing the point weight by 50-100 grains.
Jack

[lpcjon2]

Leave the arrows full length and tune, and then you can cut them to stiffen them up when you jump from 175 to 225gr.