Arrow Spine for Old Mountain Mesa

[Cocobulldog]

I am getting a "new" OM Mesa longbow, hopefully be the end of the week. Purchased used off another Trad forum. It will be my first LB, currently shooting a Bear Grizzly AMO 58 49@28 and a Bear Kodiak Magnum AMO 52 45@28. The LB will be AMO 64 42@28. I currently have Gold Tip Traditional 32 inch 400 spine with 125g broadhead & field points. Question will these work on the LB or do I need a weaker spine like 500s or 600s with same heads?

[60 Deluxe]

My guess is that you will end up using 600 spine. What is your draw length?

[DRT]

Did I miss your actual draw length? That bow is not cut quite to center on the shelf from the description and may take a weaker spine or heavier point.

[DRT]

You might get away using the arrows if you go to 175s.

[Cocobulldog]

Thanks for the responses. My draw is 28.

[Trumpkin]

Everyone has their own tuning quirks due to their form and release. That said, I'd guess you need a 500 or 600 grain spine to tune out of that bow. Fwiw, I am a bit of a weirdo when it comes to tuning... I shoot much weaker arrows than most guys, because that's just what tunes well for me. I'm currently shooting 34" 500 spine eastons (w/200 grain points no less) out of a 50@32" longbow that I draw at least a true 32".

[DRT]

Looks like a 500 would work with that point weight bit like Malachi said so many individual factors.

[Bisch]

I’m betting money the .400’s will be too stiff no matter what you try with them, short of maybe putting 300-400gr up front which will make them slower than molasses in January!

You can make .500’s or .600’s work depending on how you set them up.

All the above is based on the 42# being at your actual draw length.

Bisch

[DRT]

I'd agree Bisch except 400s show working with 175s on the 3Rivers calculator with just less than center cut. 500s with 125s. It's always run pretty true for me BUT, I knew the exact amount of center plus or minus my cuts were, they weren't specific on the Mesa.
I ran is with a 14 strand string as well which does affect it.

Coco I'd look at it there and gobfrom there. I'm shooting 400s out of a 42 pound recurve and 44 pound longbow, 27.5" draw. I'm running 150 grains up front BUT, my bow is cut 3/32" past center so that makes a world of difference.

[Cocobulldog]

Thanks Bisch and DRT. I actually received my bow tonight. The Bow says 40# but the person I purchased from said he measured at 42#. Good and bad news it is raining here in the Bastrop/ Austin area but strung it up, set my brace height to 7.5 inch and shot a few arrows, only out to 6-8 yards. Arrows I have, 400s, with 125g tips and arrows 31inch. My scale says arrows are 465 total grains. Draw is smooth, very quiet shots, arrows point to the right so believe that is saying they are stiff. Won't be able to go to Double G in Gtown till next week but will pick up a 500 and 600 to test. I want to try to keep my points at 125, both field and broadheads (Magnus Stingers) if possible as that is what I'm using with my recurve and see how those fly.

[DRT]

Stingers seem to fly well out of all my set ups. And are effective on pigs, deer, impala and wildebeest.

[Cocobulldog]

So far this morning I was able to shoot about 15 arrows from 10 -18 yards out. Now the arrows are sticking our straight, hmmm. This traditional shooting is weird but lots of fun. Bow is shooting fast, fairly quiet. and hitting the bulls eye most of the time. I LOVE this stuff!

[DRT]

Put a broadhead on it, get 10 yards and see how it flies. It may scare you.

[SJP51]

If you KNOW the centercut of the bow, you could use one of the spine calculators easy enough. I can't beleive 3Rivers doesn't have every bow they sell on their calculator. Seems it'd be easy to do.