Been following the Ashby reports and want to build an arrow with EFOC
I have some unfinished gold tip shafts and a bunch of weights to go with em.
I noticed that when you start adding a bunch of weight to the front the weight system just keeps getting longer and longer, in turn this is not actually adding the weight to the point. Not as far as balance is concerned.
Has anyone completed some arrows with over 20% FOC? If so how did you accomplish this?
What grain field points do you use and what broadheads that match the weight of field points?
Will post other questions as I think of them.
Thanks
Jason
I'm shooting a 29" GT with 100gr brass inserts and 200gr field tips/broadheads. I don't know exactly how much FOC this comes out to but they sure do fly well. Actually, I can go from 145gr to 200gr and get good flight, but I see better penetration shooting a GlenDel buck with the 200gr heads.
oh yeh
am shooting a ACS CX longbow. 53lbs @ 27 inches.
peak98,
what type of broadhead are u using?
190 grain Simmons Interceptors or 200gr Muzzy Phantoms.
i just set up some 7595 gts for my 58lb shrew. i have a 175 tip with 300 grains of brass weights behind it. im prety shure i have efoc, i dont know for shure if not its so close i dont care but i know my last setup was 17% and these are much higher, they also weigh 820. and shoot well
jrchambers,
what type of broadhead do you shoot?
Thanks
i shoot 145 stos with inserts to 175 for any thing tougher than deer and 175 razorcaps for bbears and deer, what part of ak are you from
I know exactly what you're saying. I measured FOC with the goldtip system.
With a 125gr tip my arrows measured:
1 50gr insert =16.6%FOC
2 50gr inserts=18.8%FOC
3 50gr inserts=20.6%FOC
4 50gr inserts=22.2%FOC
That's 2.2% increase from 1 to 2, 1.8% from 2 to 3, and 1.6% increase from 3 to 4.
I thought there'd be a MUCH quicker loss of return. Not all the weight is going in the very tip but it's still jacking FOC up. It's a headache dealing with that many inserts though. I'd buy the heaviest BHs that fit your requirements to keep the inserts to a minimum.
(http://peteward.com/2008photos/ASGIR/300.photo.JPG)
I use 100 gr brass inserts and 300 gr Extreem broadheads,and 300 gr Extreem points.On 29" shafts the FOC is getting up there.
There are other BH combinations that will bring up the weight, any 175 or 200 gr glue on with a 100 or 125 steel adapter works fine also.
All of my carbon shafts get a 100 brass first thing.
Pete
Pete
i have an efoc gt setup for both my 54# & 69# bob lee recurve limbs.
54# setup- 55/75 with 100gr brass insert + 245gr b/head, for a 615gr arrow with 26% foc.
69# setup- 75/95 also with 100gr brass insert + 245gr b/head, now here's the tricky part- inside (and upfront) i've got a piece of the white 8gr/" weight tube about 1 3/8" long. inside of that i've glued a piece of 4mm diameter welding rod the same length. (it fits perfectly). that bit weighs 65gr. the rest of the arrow is filled with the lighter black 3gr/" tube. total mass is 780gr @ 24% foc.
the little white weight could be made to any length you want depending on the weight you want.
the hard part is striking a balance between the finished arrow weight, the foc you want and whether it will tune before you reach your minimum arrow length.
just how i came up with my arrows. hope it helps. i think my welding rod weight idea is good because you can make it what ever you need and it all sits upfront. if you could find somthing denser than steel that would fit in the wt tube it would help more. lead or solder wire?
ozy clint what broadhead do you use and is it the same diameter are the arrow shaft.
i use an aussie made blackstump 2 blader. it is a standard 11/32" glue on b/head. so, yes it's bigger than the shaft.
I'm shooting GT3555"s with a 50gr brass insert and a 135 gr broadhead. When shot at a deer with a 45# bear Grizzly they go through the front, center and then out the other side, that is good enough FOC for me :thumbsup: I hate getting too technical.
generally with 400gr at the extremety of your arrow you get a huge EFOC if you don't use a weight tube, but don't forget that putting 400gr at the extremity of your arrow will greatly decrease your arrow spine...if one considers 5# each 25g above 125gr, it will give 55# of less..with my 50@29 ACS i shoot a 75/95 GT with a 300gr BH and a 100gr insert for a 28% EFOC
I shoot 125 grain Wensel Woodsmans glued on to a 100 grain steel adapter with a 100 grain brass insert in the front of my arrows for a total head weight of 325 gr.
GT 55/75's, and I pull 57@ 29" Arrows are cut to 30 1/2.
Shoot Easton axis 300. Cut at 29" with 2" of 2016 as a footing. A 100 grain brass insert. A 125 grain steel adapter and a 170 grain broadhead. Ends up a little over 25% FOC
I am going to try putting my arrows together with
100grn brass insert
100grn steel adapter
150grn grizzly
will use 250grn field points for testing.
Plan on using gold tip 55/75, will start with full length shafts and trim shorter as I bare shaft tune them.
I don't believe this will get me around 700grns, which is what I am looking for.
If I add weed eater string inside, will this change the spine??
i think you'll end up around 620gr total. that's very similar to my 54#@28" setup. maybe you could try a heavier b/head, perhaps a 190gr grizzly or anything around 200gr because you have a shorter draw than me and i suspect that you'll have enough arrow to get it stiff enough. that way you might be up around the 690-700gr that you are chasing. let me know what you come up with.
plentycoupe,
That's what I'm using, both with 5575 and 7595. The 7595 is about 1/2" longer than the 5575. They are about 625 grains. Got a complete passthrough on a good sized mule deer doe this year with it.
Jason
foudarme, could I trouble you for your draw length and how much your cutting off your 340 GTs. Nobody is saying if they are cutting the 7595 down any. I'm about to go to 300s.
:eek: I don' t know, guys how you can shot properly so weakly spined shafts from your bows. I get a clean relise, shoot dozen of arrows every day for 20 year but out of my bows in the range of 60-68# 29" I need a good GT 75/95 al insert 145 BH and weight tubes,I can't add much more weight on front
feliciano,
Nobody ever talks about how much center cut is on their individual bows. Some are IBO legal at 1/8" shy of center...and my Morrison is cut 3/16 PAST center.
Shooting only 48# and drawing 28 3/4", shooting 29.5" GT5575, I use a 100 gr. brass insert (used to use the GT weights with all-thread, but hated all that fussin around) and a 160 gr. head.
I have about 24% FOC. Learned recently that the cut to center or past riser equates to the arrow having trouble deciding which way to go into paradox...and can lead to some foibles in flight if the release isn't perfect.
I'll be working on shiming out the sideplate back toward center or SHY of center some to get my Foc up to EFOC (28%). I expect two things. One, I will make the arrow release a bit more forgiving, and two it will enable me to use smaller, quieter feathers than now.
Stealth is the game...so why not with my arrows having smaller quieter fletching on them?
The amount of center shot of a riser makes a huge diff in spine compared to draw weight! Most folks have to prove it to themselves. I did! :)
Doc nock, I brought that up the other day in a discussion on how much to cant the bow. The center cut and the total center shot affect the cant of the bow as well.
I have a 56# 58" Morrison Dakota and I'm shooting 31" 340 GTs with only 145 grains up front (using 5 grain weight tubes)and their flying like darts but start tweakin with heavier than 145 grain tips. I may have to go to 300 spine arrows of some sort to get at least 200 up front. The brass inserts I got didn't fit right in a gold tip (.242-6), one size for all doesn't work.
I have some 100+ GTs with 200 grain tips full length and they are a little too stiff. They have 8 grain weight tubes.
Oh ya, if you tune just right you don't need feathers at all Doc.