Another FMJ spine question....

[doeboy]

I would like to start shooting FMJ arrows. I have a Black Widow PSAX 60" 55#@28 draw, SBD string. I would like to shoot 200-250 grains up front and a 30-31 inch shaft. I need help picking a spine. 3rivers is saying .300 shaft any input or advice on picking a spine? Any tips on over all tuning these shafts?

Thanks in advance
Red

[oldbohntr]

Well, you didn't say you DRAW over 30", so .300 is too stiff if you ask me. Don't be blinded by how fast your bow is supposed to be.  Unless you're shooting really heavy weights, my experience is the .400 is the most versatile FMJ.  I used a 56# Toelke in Africa and killed a lot of stuff with a .400 with 250 grain Tuffheads.  To be honest, the .340s were so close as to be ALMOST interchangeable.....but the .400s were simply the right arrow.(28" draw on a 28.75" arrow, btw.)  The .400 is not a lightweight in any category, and I have not found the .340 to be the right arrow out of any bow less than maybe 57-58#, and the .500 can fly well out of bows a bit over 50#....but the .400 will do it as well or better.  

If you are drawing near 30 or more, then, of course, I could be way off.  But, I've also found the FMJ .500s to act stiffer than other carbon .500s.  So, I'd still bet you'll find the .340 will be better than the .300.

They're a heck of an shaft, in any case. Pay lots of attention to shaft and feather preparation even to the point of sanding if you aren't going to dip/wrap.  The surface is slick and will shed fletchings easily.

[yeager]

I've been shooting FMJ's for the past 3 years and love their performance.  My bow is a Bob Lee Classic, 60"/55#@28" and my draw is 26.5.  I use the standard H.I.T. insert and the old Bear razorhead with broadhead adapters (150 grains). My string is a 8190 10 strand. I used Stu's calculator and with that, it recommended a 500 spine @ 28".  The data was spot on and they fly great. With 250 grains up front and and arrow length of 30-31", I would say a 300 spine would most likely be right. IMO, I would try Stu's calculator to see if it is in the ball park.  Good luck.

[Tedd]

You would need a little more up front or use the .340
My pch is 51@29 drawn to 32" I have 300 grains up front. using .300 deflection shafts. (three rivers trad only shafts).
Got them flying like bullets. I use the whole 33" shaft.
Question, why the FMJ shafts? The Trad only cost less I think. They are very straight and extremely constant. Diameter is 5/16" with I think is small enough. Not being critical. Just wondering why.
Tedd

[Steve O]

I know Black Widows are supposed to shoot heavier spines but 300s in a "normal" bow would be for a 75# IMO.  

I draw 30" and use full length 340s with 250g heads out of my 55@28" NON Black Widow high performance recurves.

I think you would be a LOT better off with 400s

[Jake Scott]

I shoot .400's cut to 29.5 with brass inserts and 200 grain heads.  They bare shaft great and fly like lazer beams from my 53# recurve drawn to about 27 inches.  Probably the only arrows I'll ever buy.

Jake

[tracker12]

My buddy's Leon Stewart Slammer 50# at 28 throws a great 500 spine arrow with 200 grains up front and he is shooting them full length.  I have been using the 400's drawing around 46# and 200 grains up front.  I have been using these since they were previously used out of my wheel bow.  My next dozen will be 500's.

[DarkTimber]

My BW PSA is 54 at 28 and I draw 29" so I'm getting about 57 lbs out of her.  I shoot the 340s cut to 30.25" with standard aluminum insert and 250 gr points.  They fly like lazer beams.   I think you could also use the 400s with a little less point weight

[damascusdave]

Full Metal Jackets, because of the cost, are not arrows you want to buy a dozen of until you know you have the dynamic spine nailed...and the only way to nail the spine is to shoot them...I think 3Rivers will actually make you a test kit which makes that process rather simple...I find the FMJ does not react favourably to changes in point weight as a method of changing the dynamic spine so you need to start with the correct static spine...I just happen to have a friend who has a small arrow business, who also likes them so I can buy any quantity I want...I do not even bother to fletch them any more...he can tape fletch on them so tightly that one cannot rip if off with max pull on the feathers...my guess, if you have the 29 inch draw that 30 to 31 inch arrows imply, is that the 340 is what you will end up with depending on the effect of that string on dynamic spine...that same friend is becoming a master string builder and we are doing that final bit of tuning with string construction to allow us to shoot the arrow set up we like for that bow, so effectively tuning the bow to the arrow

DDave

[doeboy]

Guys,
Thanks for all the great info.I draw the bow just under 29" so i would assume im arround the 56-57# area. My current arrows (AD's) are cut to 30 1/2" but the length doesnt bother my as much as a proper tune. Like stted above, i'm trying to get as much info before i make a purchase. The test kit may be the way to go, and im glad i didn't follow the "Arrow guide" in three rivers.i would be selling 11 arrows on Fle*****!

Red

[MnFn]

Don't know if this helps but I have some FMJ 340's tuned pretty well to my 60#  @28" Pronghorn.  I have a 75 grn insert in it and 160 grn two blade STOS. Currently they are 29.75", I may try some 180 grn  grizzleys, but they are flying nice as they are.

[bucksakemmer]

I am trying to do the same thing, I have a Widow PCH 47@ at 28 and I draw to 29.5
according to Stus calculator I need a 300 spin arrow. I have been  trying to bare shaft this bow with FMJ 400 and ACC 340 and 300
So far the 300 ACC are shooting the best, not good but the best.
I should be able to shoot 400's but can't get them to tune.
I plan on devoting tomorrow to the problem. I has me whipped so far.
25o grain tuff heads the FMJ have 50 grain inserts the ACC have standard aluminum.
They all bare shaft week except the 300's

[Steve O]

Originally posted by bucksakemmer:
I am trying to do the same thing, I have a Widow PCH 47@ at 28 and I draw to 29.5
according to Stus calculator I need a 300 spin arrow. I have been  trying to bare shaft this bow with FMJ 400 and ACC 340 and 300
So far the 300 ACC are shooting the best, not good but the best.
I should be able to shoot 400's but can't get them to tune.
I plan on devoting tomorrow to the problem. I has me whipped so far.
25o grain tuff heads the FMJ have 50 grain inserts the ACC have standard aluminum.
They all bare shaft week except the 300's

I guess that is why I don't use a calculator or shoot a Blac Widow...that setup   screams 500s to me.  I can't get a 300 to be weak with a  full length shaft, a 300g head and a low 60# @30" bow!

[jkm97]

Originally posted by Steve O:
 

Originally posted by bucksakemmer:
I am trying to do the same thing, I have a Widow PCH 47@ at 28 and I draw to 29.5
according to Stus calculator I need a 300 spin arrow. I have been  trying to bare shaft this bow with FMJ 400 and ACC 340 and 300
So far the 300 ACC are shooting the best, not good but the best.
I should be able to shoot 400's but can't get them to tune.
I plan on devoting tomorrow to the problem. I has me whipped so far.
25o grain tuff heads the FMJ have 50 grain inserts the ACC have standard aluminum.
They all bare shaft week except the 300's

I guess that is why I don't use a calculator or shoot a Blac Widow...that setup   screams 500s to me.  I can't get a 300 to be weak with a  full length shaft, a 300g head and a low 60# @30" bow! [/b]

My Widow and 8 strand SBD really likes them stiff as well.

[oldbohntr]

I'm with you, Steve.  I can't get anything meaningful from a calculator or other folks' results.  No offense to anybody, but with shafts like the FMJ, you just have to find a few of each and give it a go.  I have a few extra full length .340s and I'll bet others would share too.
People don't always hear when I say FMJs "shoot stiffer" than other carbons and they definitely hit higher than the same spine in Carbon Express(I know that's not apples vs apples!)

I am convinced the FMJ is the best shaft I've tried in 40 year of shooting. It may not the most versatile, but if you can make it work, it's a  winner!   If ya want to try it, it has a significant cost. It's sometimes hard to get around that reality.

[oldbohntr]

I think Mike may have a point.  In any case, doeboy, I'd still suggest finding one or two of each shaft and giving it a go. I'll bet some money that you'll find either a .400 or .500 FMJ is the right one for you(as per above, I am not so confident that a .400 or .500 spine in some carbon arrows correlates to the same in FMJs!  In any case, I'll bet significant money that a .300 is NOT the right spine for you!!

[doeboy]

Thanks guys. Looks like I will buy a test pack and see what the bow likes. Thanks again for the advice.

Red

[Steve O]

Good call Mike