long draw and foc

[daveycrockett]

How do you guys with long draw get the high foc on your shafts? For me I have to shoot some of the stiffer carbons and can't load the front up. Was playing around today with an arrow dynamics trad heavy cut to 31" anymore than 175gr. and it gets to flying funky. It shoots 125gr. and 150gr. heads great.

[Steelhead]

I have not used that many brands of carbons and have only been seriously been using them for about 8 months.I have had good luck with CX-250s and 200 grsins up front.50 grain brass insert.I draw about 30 and cut my arrows 30.5 inches.Bow poundage around 50 to 56#sat 30.I am getting very good flight with this setup

Shooting a 61#s at 30 Kajika might handle a 250 well.Not sure but maybe a 350 would work for you with alot of weight up front.

[Matt_Potter]

Welcome to the Monkey arm club - I have to cut mine at 32".  Take a look at the Carbon express Maxima shafts they are fairly light for their spine.  If the shaft is light enough you can go with a heavier spine than you would normally shoot and just stack weight on the front until they fly right.  But, the shaft has to be physically light in weight or when you start stacking weight on it they get silly heavy.

Right now I am shooting a maxima 350 with 250 grain up front. Out of a 50lb Morrison.

matt

[daveycrockett]

Thanks, have played with the 350's a little also. I can shoot it with a regular insert and 200grains up front at 31" long.

[katman]

You can build up your strike plate a little at a time using the point weight you want until your in tune. With the AD shaft make sure the seam is perpendicular to the bow.

[Richie Nell]

Davey,
I am using the GT Big Game 100's pulling 31".  In order to get high FOC you must start with an arrow that is TOO stiff.  My arrows are from 840 gr. with 29% EFOC to 1029 gr. with 31.7%.

I also have 500-600+ gr. up front.  They fly really, really well and flatter and faster than I would have thought.

I am not familiar with the AD shafts but maybe it is the design of the shaft,???. If they are TOO stiff to begin with I can't imagine why they wouldn't weaken back to the middle as you add weight to the front.

[Big Sneaky]

I draw a 58# ACS CX to a little over 30.5"  I shoot 300 Axis cut to 31 1/2" with a 100 gr brass insert and 125 gr head.  I can also shoot a 150 gr. head and still get good bareshaft flight.  Having a long draw kind of limits some of the shafts I would like to shoot, but having that extra long powerstroke makes up for it.

[BobW]

I've given up chasing EFOC.... (I draw 32"+).  It just isn't happening in my world.  I just shoot wood shafts that are starting out at just over 700 gr.  That with a 135 - 145 gr tip hits like a sledge hammer.  Spine class for a 60# bow is 105# to start.

Now, if anyone would make a 34" raw shaft in carbon.......

[Rob DiStefano]

imo, it takes some thoughtful planning to build an arrow of specific length. gpp weight and foc balance for a specific bow.  easier done with carbon and alum shafts than woodies because of the insert and adapter versatility.

my main hunting bow is 55# @ 29" and i use 29.5" arrows.  my hunting arrow goal was to use carbon shafts and a final gpp of at least 11 and an efoc of at least 20%.  

i started with a number of different carbon shaft brands and models, narrowed it down to the cheap beman ics, tested out different spine models and selected the 500 spine.  these are very lightweight 7.3gpi carbon shafts.  light shafts allow a greater range of front end loading for higher foc while not getting too high in the arrows mass weight for bows in the 45-55# holding weight.  

i knew i wanted to load up the front end so i went with 100gr brass inserts.  unpointed, the arrow with insert, 4" four fletch and bohning signature nock weighed 335gr.  

it's easiest to find 125gr broadheads, and knowing i wanted a a head that makes holes and not slits i decided on the tri-blade woodsman.  coupled the 125 woodsman with a 125 steel adapter, added the 250 grains up front yielded a 585 grain broadhead arrow with 10.64 gpp and 28% efoc.

replacing the 250 grain woodsman/adapter with a 300gr vpa terminator gives me a 635gr arrow, 11.55 gpp and 29% efoc.  mmmm, mo' better.

the gpp and efoc thing are just icing on the cake, and the most important things are still a good flying arrow, hair shaving broadhead, real good shot placement.

woodies are harder for me to hit both weight and front end balance.  i typically use hex pines in 55/60# spine, use the braveheart wood arrow weight footing jig to add nearly 100gr to the arrow's front, and then a 190gr or more broadhead.  these arrows will typically be in the 600+gr range and have an foc of between 15% and 20%.

woodies are trad nostalgic fun, but carbons are better ... for me.      ymmv.

[Matt_Potter]

Rob,

You were able to bump your head weight on those shafts by 50 grains and not have the bare shafts flying sideways?  I have found when you are dealing with long shafts - 32" in my case - 50 grains will make or break the deal.

Matt

[jhg]

NOT an expert...

I draw 30" and am shootinng a 60#@30 (actual #'s), Howatt Hunter.

I am shooting full length ICS 400 BowHunters, footed, a 190 grn BH, steel screw-in-glue-on and brass inserts for about 625grs, They fly great from my 60# recurve and 58# longbow.

FOC is there too but I never worried about it too much. Wanted it but didn't worry. They balance toward the tip someplace and  thats good.

Joshua

[Rob DiStefano]

Originally posted by Matt_Potter:
Rob,

You were able to bump your head weight on those shafts by 50 grains and not have the bare shafts flying sideways?  I have found when you are dealing with long shafts - 32" in my case - 50 grains will make or break the deal.

Matt

nope, not even a hint of a bad flying arrow for me - and that's with a bare shaft.  

if your arrow is carbon with an insert, try screwing in the heaviest point you can find, and give it a try - better even without fletching.

postscript - i should add that my bow's ultra thin leather arrowplate is a hair over 1/8" past the bow's vertical centerline.  i also aim the arrow, not the bow, and i have at least a very decent in-line form and a modified mediterranean string grip and release.  personally, i think a lotta, and i mean a LOT, of upfront weight to an arrow aids tracking, allows it to recover from snaking the paradox faster, makes arrow tuning easier, and probably other good stuff like penetration.  also, i have not tested any of this with alums or f-glass shafts let alone woodies.  carbon arrow shafts are just *different* from other shaft materials, and for me that's been a real good thing.  ymmv.

[xtrema312]

Just build out the side plate.  That would help some.  If you don't want to go as far as it would take then how about footing?  Maybe internal?  I have not done it, but I would think you cold get FOC plus stiffen the shaft so you can get even more weight up front.  I see a shaft stiffness difference between a 100 gr. brass insert and the same amount of weight in point with a short light insert.  The length of the brass changes the spine.

[wisconsin wood butcher]

heres what i'm playing with uncut CE250's with 100gr. brass insert 145 tip 7"s of 5/16 dowel internal with 4 -5" parabolic's .50 to 55 #s at 30"s depending on bow i also have  a uncut 250 with a dowel rod and i believe 145gr. brass insert for gluing a 130gr lw grizzly. the feild piont arrows fly great for me. thats my 2cents

[Rob DiStefano]

fwiw, imo, and what works for me ...

i spent a lots of time (and money!) messing with carbon shafts/arrows and found that, unlike the manufacturer recommended shaft spines, much lower spine rated shafts were the easiest to tune.  in fact, i could never tune those stiff carbons well.  

as a result, years ago, my original beman ics 500's weighed in at 535gr for my 55# longbow.  they flew great but didn't pack the punch i thought they should.  so without any ado, or even knowing i was messing with gpp and foc,  i just upped the point weight 50 grains, for a 585 grain arrow.  

i fully expected a weakened spine that'd need adjusting with more weight at the nock end, or maybe an inner weight tube to stiffen up the shaft.  instead, the arrow tracked better.  i stripped off the 4-fletch feathers and bare shafted - same great flight and one hole paper tests.

subsequent tests with total arrow weights between 620 and well over 700 grain arrows (all with increased front end weighting) showed the same great bare shaft/arrow tracking.

i dunno or care why this happens.  just happy it does.  my best guess right now is that it's a combination of things that greatly starts with the *dynamic* spine properties of carbon arrows, not the *static* spine properties.  i'll leave the rest to the physics techies to argue it out.  

the only really low foc, highly stiff carbon arrow that flew great out of bows ranging from 42 to 58 pounds of holding weight is the tapered ad trad.  and yep, the more front end weight i managed to cram on, the better it flies ... for me.  

ymmv.

[bigbellybuck]

I have to shoot a .340 spine and my longbow is only 50# @ 30. I just can't get a 400 to fly right even cut down to 30 in. and shootin 125 gr. heads. But a .340 spine that weighs 8.3 gr. per in., cut to 31.5 in. with a 200 gr. point gives me a little over 500 grains and they fly like darts! I don't understand it but it works.

[Rob DiStefano]

Originally posted by bigbellybuck:
I have to shoot a .340 spine and my longbow is only 50# @ 30. I just can't get a 400 to fly right even cut down to 30 in. and shootin 125 gr. heads. But a .340 spine that weighs 8.3 gr. per in., cut to 31.5 in. with a 200 gr. point gives me a little over 500 grains and they fly like darts! I don't understand it but it works.

dang carbons ... go figure!

i'm convinced that at least a fair part of the carbon/bow equation is the shooter - i.e., how they shoot: form, aiming, release and follow through.

[pdk25]

Wrestling with the same problem myself, and I only draw a little over 29".  Anything over 250 grains up front makes my 300 spines axis arrows too weak for my 71@28 slammer.  Ad trads fly okay with 300 grains up front as long as they aren't longer than 29 1/2".  Tried the aquarium tubing trick to get the weight up and they still get weak.  Getting a 75@28 morrison dakota and don't really feel like messing with the sideplate.  I ordered a half dozen nitro stinger gold that are .215 spined and will see how they work.  They also are only 9 gpi, so that should help with FOC, although I'm gonna want to get the total weight up mostly in front.  Hope it works.  The only thing after that without double shafting or complex footing would probably be the ad big game, which are .200 spine.  They are 10.5 gpi which would help with the overall weight some but not the FOC.

[Matt_Potter]

Rob,

I'm shooting axis 400 with 100 brass insert.  I think I have fair form and a clean release (shoot 2 under).  If I put a 150 200 and 300 point in 3 bare shafts they will all group with fletched arrows but, I can tell you which shaft has which point by the angle of the bare shafts compared to the fletched shafts.  Are you tuning by arrow grouping or shaft angle.

Thanks

Matt

[HATCHCHASER]

If you will put the internal 100 grain brass inserts in the mfx shafts they will increase the front of center without weakening the spine.  You can also glue a second insert behind the first one.  I think its because the insert is farther back.  Also the smaller diameter shafts puts the arrow closer to center.  It also depends on the center cut of your bow.  Bows cut past center tend to take stiffer spines.  A carbon arrow when cut shorter does not respond to point weight like a full length shaft does.  Us long draw guys have more problems trying to acheive foc.  I tend to buy more 75-95 gold tips and 400 and 340 of other shafts.  I keep some of everything for that new bow that is bound to appear.  ymmv.