Determining point weight problem

[FrankM]

I've been shooting my 28" 5575's out of my 51# bow with a 27" draw, rest centered. My bow spine is 58 according to Stu.

With 125 gr. points, 70 gr. weights, they weigh 458 gr. FOC is 20.3%. Dynamic Spine is 75.5 according to Stu. I paper tuned these with a 200 gr. point.

If I put on 200 gr. points, the Dynamic Spine is 59.1 (close to bow).

I've been trying to use the horizontal and vertical tape method to try to see if the arrows shoot differently with different weight points. I've tried 125, 145, 175, 200, 250 gr. points.

I've shot from 5/10 yards but the arrows all act the same. If I settle down and shoot with good form, I can make small bullseye's with all arrows going in nock straight.

I thought the arrows would act differently. Go left, right, not be able to group, etc.

Surely, they aren't supposed to act the same with such a difference in point weight? What can I be doing wrong?

[skarcher]

I have found that with carbons, they are far more sensitive to length than tip weight. 1/2" will make quite a difference, but a difference of 50 grains tip weight  is almost unnoticeable. You should however see a difference between 125 and 250 gr points, but it may not show up till you start testing at 20 yds or more.

[legends1]

Im not sure the bow you are shooting but if your bow is cut 1/8 past center and with a radius shelf and window you will be able to shoot various spine arrows.This maybe what you are seeing

[FrankM]

I'm shooting a Martin Takedown Recurve with a NAP flipper rest. Maybe I should put 125 gr. points on two arrows, 250 gr. points on two arrows, back up and see what happens?

[JimB]

I don't think 5-10 yards is enough to tell a difference.I don't paper tune but use the bare shaft planing method and I can see a difference in 5-10 grs of point weight on the bare shafts.

I start at 15 yds gradually work back to 30 yards when I think I'm close.If I only shot fletched arrows,I wouldn't be able to see a difference in 50 grs of point weight.

With the planing method,you just tune until the bare shafts and fletched group together.

After they look good,I shoot the same weight broadheads and the broadheads may show slight tuning discrepencies that even the bare shafts didn't.Usually a little tweaking of sideplate is all that is needed if anything.Again,shooting fletched broadhead arrows alongside fletched field point arrows until they hit together out to 30 yds.

If you are only shooting fletched field point arrows,especially at close ranges,you won't see much difference.

[excelpoint]

Originally posted by skarcher:
I have found that with carbons, they are far more sensitive to length than tip weight. 1/2" will make quite a difference, but a difference of 50 grains tip weight  is almost unnoticeable. You should however see a difference between 125 and 250 gr points, but it may not show up till you start testing at 20 yds or more.

I have found the same thing. Carbons seem far more sensitive to length then tip weight. I bare shaft out to 30m and have found only a minor difference between 125gr and 200gr points. Take 1/8th of an inch off and the difference is far more noticable. This is out of a Jim Jones Firefly TD longbow which is cut 3/16th(about 1/8th past with side plate) past centre.

[wingnut]

I find that with fletched arrows the BAB (big A$$ broadhead) planing method works well.  Setup one arrow with a target point of given weight and the other with the same weight and a large BH.  I usually use snuffers.

Mike

[Mint]

Maybe it is the flipper rest. I'm shooting 55/75's cut to 28" with 50gr brass inserts and 200gr points and i notice a difference when I shoot 175gr points and 225gr points. I'm shooting a 55lb palmer recurve.

[FrankM]

I'm thinking it's just gonna be cheaper and faster to bareshaft tune. Though I hate to take off feathers.

[SlowBowinMO]

Originally posted by wingnut:
I find that with fletched arrows the BAB (big A$$ broadhead) planing method works well.  Setup one arrow with a target point of given weight and the other with the same weight and a large BH.  I usually use snuffers.

Mike

X2.

That is exactly the way I prefer to tune and it will yield excellent results.  Since your arrows are already fletched, why not go that route?

A big Snuffer or Magnus 4 blade will definitely tell you what your arrows are really doing!  :D

[FrankM]

Say, I got some 140 gr. Zwickey's. You think I should put those on and compare with 145 gr. field points?

[John3]

Frank,

Cut the fletches off of one arrow and bare shaft it...

51# bow with a 28" 55/75 "should" be too stiff...
 
Bareshaft until you think it is close.. Same length fletched shaft tune with broadheads installed...  Only accept perfect arrow flight with broadheads...

JDSIII

[Greg Skinner]

I agree with those who suggest tuning with big broadheads.  I use 200 grain Ace and 3 3" feathers at 20-25 yards. I'm shooting 55-75 GTs cut to 28 1/4, 100 grain brass insert and 100 grain steel adaptor, 57# @27" Hill.  It is cut about 3/16 from center.

[FrankM]

I'm a bit confused. Isn't the purpose of shaft tuning to determine what weight points to use? If so, why jump to broadhead tuning without knowing what weight?