I am goin to be making up some arrows for my elk trip in Sept. I will be shooting my #55 Bear Montana longbow, its cut just shy of center and isnt really a speed demon. I currently use a 145gr head on a 23/64 cedar arrow that weighs 600gr and is 60-65 spine. I want to beef up to a hardwood shaft and shoot a 160gr head on this trip(something in the 650-700gr range). Any help on proper spine would be great! I plan on callin Allegheny Mountain Arrow Woods and get a dozen Douglas Fir or maybe Ash!

If you are shoothing 23/64 no with no problem then a hardwood shaft of 60/65 should be the ticket. To be exact I need to know the length of your arrows and your draw length and if using a ff string or B50.

That physical weight is a little hard to find, but not impossible, in Doug fir.  Pretty easy to get in hardwoods.  Hardwoods don't recover from paralax as fast as softwoods like cedar and doug fir.  If you use a hardwood, you might need to  bump spine another 5# or so.  If not, I second what Danny said.

Danny:  Did you get my email re forgewoods?

I am shooting a 3Rivers TS1 String on the bow and have a 28" draw! I cut arrows at 30" and have a 29" arrow from nock groove to back of point. Have no preference on if the shafts are 11/32 or 23/64, just want to get a properly spined arrow thats all. It shoots well with the 23/64 cedars and 145gr head at 60-65 so id think a 65-70 with the 160 would be bout right with the fir shafts.

Not enough experience here to answer your question, but I'll be keeping my eyes open because closely related to similar ?

Ok,

Go up one spine from draw weight=60#, subtract 5# for non center cut=55#, add 5 for ff string-60#, add 5 for every inch of arrow length above 28"=70#, add 5 for head over 145=75#.

So, your 60/65 would be ok if doug fir, 65/70 might be better with the 145 gr head, but for a hardwood and any head over 145gr,I would go 70/75

answered your email Jerry.

Danny

QuoteOriginally posted by Danny Rowan:
Ok,

Go up one spine from draw weight=60#, subtract 5# for non center cut=55#, add 5 for ff string-60#, add 5 for every inch of arrow length above 28"=70#, add 5 for head over 145=75#.

So, your 60/65 would be ok if doug fir, 65/70 might be better with the 145 gr head, but for a hardwood and any head over 145gr,I would go 70/75

answered your email Jerry.

Danny

65-70 or 70-75 w/160grn points. You could even go to 30"BOP, too.

So which one is it? I have found two arrow spine charts. One for a centershot longbow/recurve and a longbow/selfbow! I dont really get that feel out of it to consider it a performance longbow, its an accurate shooter with some zip with a heavy arrow and very quiet. What chart to use and what spine? I am shooting the 60-65 in cedar, fir should act bout the same so i should just go up one spine weight not two correct. So 160 head, #55, 29" arrow=65-70 spine?

What about Laminated Birch?  I have some that weigh around 750 with a 145 grain Eclipse Broadhead.

Thats heavier yet!!! I know my ability is limited to 25yds, and i think if i shoot whatever arrow/combo im goin to be using in the fall, starting now and hit a few 3D shoots this summer id be dialed in to the trajectory drop difference! Im thinkin a finished arrow in the 625-650 with a 145-160 broadhead would be good elk medicine, and would use on deer too!

On your other thread you said you are currently shooting 600 grain arrows with your bow. I am a supporter of heavy too-but shooting well and arrow tune are likely just as important-your tackle sounds fine.
I would suggest staying with your current outfit (as long as your broadhead is a sound choice) and concentrate on the other 100 things you need to tend to and have a successful Elk hunt, don't forget the camera!