What carbon shaft spine for a 40lb ACS

[Onions]

I have a 40lb @28 ACS Longbow, that needs some new carbon arrows!
My draw length is 29", I would like to shoot at least a 150gr head, but don't want to go over 200. For feahters I will shoot 3 X 5.5" parabolics
Do I need .500 or .400 spine shafts?
Would like to hear your suggestions!
Thanks

chris <><

[jlowrey75]

I would guess 500 spine would work. I use 400 spine cut to 29" with 250 grains up front and draw 50lbs @ 27" and Btw I shoot Easton bloodlines with my A&H ACS. Hope it helps.

[gonefishing600]

It's gonna be close either way. I have a 46#@28 and shoot .400 GT trads 5575 cut 30" with 145gr field point. If you draw 29" your gonna want a minimum of a 30" shaft. I think the .500 would work with a 150gr up front. If you went with the .400 you would probably end up with a 31" shaft and 150 up front.

[Friend]

A 500 spine...~30 3/4"...175 gn tip should be in the ball park.

or

A 500 spine...29 7/8"...200 gn tip should be in the ball park.

[damascusdave]

I found my ACS CX with very similar specs drawn to 30 inches to be quite forgiving of spine differences...I would lean toward the 500 spine, but I suspect you could make the 400 work as well if you leave them long and front end load them a bit...not sure if you bought the bow new...my 66 inch version came with a draw weight sheet indicating 41@28, 43@29 and 45@30 so 2 pounds per inch after 28 inches

DDave

[Onions]

Thanks everyone! I had a feeling that my setup was on the fence between 500 and 400's.
I have shot some 400's at 29.75" with 300gr on the front end. Seemed to shoot fine, however I did not bareshaft.
Just recieved some 3555's from BigJim, will start tuning these this week.
Thanks again!

chris <><

[BigJim]

I would be looking more at the 1535's (.600) or possibly the 3555's (.500)

The 3555's are now 32"s long so they could be left longer if need be to keep them from being to stiff.

Good luck, BigJim

[damascusdave]

Not often one gets a step ahead of Jim...now big porkers on the other hand seem to have his number right now

DDave

[JRY309]

I would go with a .500 spine for the ACS.I have a 50# A&H ACS and shoot a .400 spine out of it,even with my side plate built out alittle.ACS are hard and fast shooting bows,it took a stiffer arrow then my other bows of same weight.

[JohnV]

I have several ACS takedowns. Unless you build the arrow shelf out, they like more spine than what you would predict since they are cut past center. Assuming you want to use heavy points, go with the 0.400 spine. I use the 0.340 spine with my 53# ACS and 28" draw with total arrow length of 30".

[The Night Stalker]

My bow likes a heavier spine, axis trad 340 for my 64 inch 47 @29 limbs.  Axis 400 for the 66 inch 45@29 limbs. Both set up have 175 grains up front.