Bow Tuning Help-Confused

[pronghorn23]

I'm in need of some help with bow tuning.

Last year I was shooting good and arrows were flying good. This year arrows are in good groups but not on target and porpoising.

Here's my equipment:

Bow:         64" Vintage Archery Savage Flatbow
            55# @ 28"

Broadheads: 125g 2-blade Magnus II

Field Points: 125g standard tapered field point

Arrows: 60/64 lb 23/64" tapered POC fletched with
       three  5 1/2" LW shields. Arrows measure
       28 3/4" from throat of nock to the back
       of the broadhead/field point.

String: P450+

Brace Height: 6 3/4", Instructions suggest 6 1/4-
             7 1/4".

I shoot right handed.


My broadheads hit to the upper left of the target. They hit the target with the nock end to the right so I figure I'm probably overspined.

Field points are lower but to the left of the target.

Bare shafts are hitting to the right of the target and were landing in the target nock high (to the tune of about 30 degrees!) The bare shafts are landing with the nock to the left.

I lowered the nock point which brought my bare shafts down onto the target but to the right of the target. They are still landing nock high in the target and when I release I can see them curve to the left of the target then land to the right of the target, just like a beautiful curve ball.

I'm confused as far as what to do. With fletching, broadheads or field points it seems I'm overspined. Bare shafts seem to be underspined.  :confused:

[vermonster13]

Are you sure that all your arrows are actually spined the same?

[Ross]

Go to O.L.Adcock's webpage.He has a set-up for tuning.Good info-should get you off with minimum
confusion.
Ross

[pronghorn23]

I'm not 100% sure because I don't have a spine tester but they were purchased as a matched spined set.

Ross, thank you I'll check it out now.

[vermonster13]

With the results you're getting I would guess they aren't matched real close.

[madness522]

Without a spine tester one of the things you could to is take a couple of the arrows, remove the nock and glue on another nock turned 90 degrees from the way it was originally.  If some of the arrows have the nocks with the grain and others across the grain it could affect how they fly and show different spines.

[O.L. Adcock]

Weathermen in NM can be right 95% of the time if they just predict clear and sunny. You can be right on tuning problems 90% of the time just saying go up in point weight!

No wonder you're confused, you are mixing 2 different tuning methods that aren't compatable. Either use the "kick" method looking at nock direction/shaft angle or the "planning" method which looks at group relationships. The "kick" method is unreliable IMO.

Stick with just the BH's cause BH's and bare shafts will tell you the same thing and the Bh's are all that matters this time of year.

A person can be spined correctly, or a touch overspined, over spined, or WAY over spined. You are on the edge of being WAY over spined. Stiff arrows both BH's and bare will group left of fletched field tips..Unless you are WAY over spined in which case the tail of the arrow hits the shelf/window causing them to go right. That's whats happening with your bare shafts but they aren't quite bad enough to show up in the BH's. You might have some arrows nocks too tight, be sure and fix that first...Tell us what happens!   ....O.L.

[Shawn Leonard]

Listen to OL, the kick method is tough as ya need a super consistent material to shoot into. I say ya should be shooting closer to actual 55# shafts or up the point weight and check your brace compared to last year,. Shawn

[WildmanSC]

I would guess you need some 50-55 spine or 55-60 spine shafts.  I'm shooting an ACS CX with one of OL's risers and a 64", 52#@28" set of A&H limbs.  The bow shoots either .500 spine Beman MFX carbons at 29" BOP with 125 gr up front or Easton ST Axis .400 spine carbons 30" BOP with 125 gr up front equally well.  The bow is so spine tolerant it even shoots aluminum 2013s into the same group as the MFX and Axis arrows at 20 yards.

Bill

[pronghorn23]

Just wanted thank everyone for their help. I ended up ordering a set of test arrows and starting over. Ended up with 50/55's. They're flying alot better!