[Tailhunter]

Here are the particulars:

Ross Cr337
37” a/a
7.75 brace
303 IBO
Set at 65lbs. 30” draw
Carbon Express Maxima 350
bare shaft 28.5”
360 grains total
Point 85 gr., Insert 12.3 grs.
Blazer Nock 10.5 gr.
Fletched with 3 blazer vanes, which weigh 17.8 grs.

I have a left-handed tear, which won’t go away. I shoot a Trophy Taker rest and a Scott shark release.

Can someone run the numbers for me and see what’s up? Thanks… :wink:

 

[Dado]

By OT2 your arrows are WAY too weak. Even with #60 they're still on the verge of the red zone. The setup might work with 10 grains less in the tips and DW to at most at #60.

 

[MMMB]

I'd stiffen up those arrows....

 

[elkreaper]

Taps shows those arrows to spine from your bow at 70.5 #

If you put a 100 grain tip on it and crank your bow up to 68.5 they should spine just right

 

[elkreaper]

By TAP your arrows are WAY too weak. Even with #60 they're still on the verge of the red zone. The setup might work with 10 grains less in the tips and DW to at most at #60.

Try it again you did something wrong these arrows have a dynamic spine of .35 which is normal for high energy 70# bows.
he could switch to a .40 spine and keep the current weight of the bow

 

[Dado]

Taps shows those arrows to spine from your bow at 70.5 #

If you put a 100 grain tip on it and crank your bow up to 68.5 they should spine just right

Don't you feel this might be wrong? I mean spine of .404 with 100 grain tips at #70 and 30'' DL?? Makes you wonder why are there spine selections as low as .340 or .300? For #100 pound bows? I doubt it...

In any case, I'd here believe OT2 more than Tap, but 1st I'd trust my own judgment and bare shaft tuned them as well...

 

[Dado]

Try it again you did something wrong

Yeah I wrote TAP instead of OT2 corrected it now.

 

[elkreaper]

Taps has alway gotten me shooting bullet holes. Also he is using 85 grain tips not 100, there maybe your first problem.

 

[Tailhunter]

If arrows are too weak then going from 85 to 100 grain will only exacerbate the problem. If they are too weak with 65 lbs. then how will 68.5 lbs. and heavier tips help? What is it really too weak or too stiff? ...:sad:

 

[Tailhunter]

 

[elkreaper]

Your arrows are NOT to weak they are a .35 spine. At 65# a .40 would suit you better( or using a heavier tip). I'm betting Dado used his calculator wrong. Taps and on target are alittle different but NOT that much.

 

[Dado]

Sorry, my mistake - I ran the 250s not 350s... It should work better with like #68 and 120gr. tips... But nevertheless, bare shaft tune them in any case.

 

[elkreaper]

Sorry, my mistake - I ran the 250s not 350s... It should work better with like #68 and 120gr. tips... But nevertheless, bare shaft tune them in any case.

I've done it a few times my self.:embara:

 

[nuts&bolts]

Drop your draw weight to 60 lbs and try again

Here are the particulars:

Ross Cr337
37” a/a
7.75 brace
303 IBO
Set at 65lbs. 30” draw
Carbon Express Maxima 350
bare shaft 28.5”
360 grains total
Point 85 gr., Insert 12.3 grs.
Blazer Nock 10.5 gr.
Fletched with 3 blazer vanes, which weigh 17.8 grs.

I have a left-handed tear, which won’t go away. I shoot a Trophy Taker rest and a Scott shark release.

Can someone run the numbers for me and see what’s up? Thanks… :wink:

I assumed you have the 80% let off cam.

Take a full turn off your limb bolts,
and try again.

Take 1-1/2 total turns off your limb bolts,
and try that.

If you drop your draw weight,
1/2-turn at a time,
things should get better. Somewhere around 60 lbs
or 61 lbs of draw weight will be your sweet spot.

 

[elkreaper]

I assumed you have the 80% let off cam.

Take a full turn off your limb bolts,
and try again.

Take 1-1/2 total turns off your limb bolts,
and try that.

If you drop your draw weight,
1/2-turn at a time,
things should get better. Somewhere around 60 lbs
or 61 lbs of draw weight will be your sweet spot.

That will make it worse his arrows are already to heavy of a spine

 

[Dado]

I assumed you have the 80% let off cam.

Take a full turn off your limb bolts,
and try again.

Take 1-1/2 total turns off your limb bolts,
and try that.

If you drop your draw weight,
1/2-turn at a time,
things should get better. Somewhere around 60 lbs
or 61 lbs of draw weight will be your sweet spot.

With all due respect Lug Nut, all of these shaft selectors tend to go on the stiff side, so most likely my suggestion of #68 and 120 grain tips would still show a stiff arrow reaction, but it will be better than the current one...

 

[nuts&bolts]

With all due respect Lug Nut, all of these shaft selectors tend to go on the stiff side, so most likely my suggestion of #68 and 120 grain tips would still show a stiff arrow reaction, but it will be better than the current one...

Dado:

It depends on the percent let off.
In the Equipment Tab,
when you select the brand and model of bow,
in this case a 2006 Ross CR337
the program shows a default percent letoff value

of "65/80".

If you leave this box (white color) unchanged,
even though the program shows you both values,
it really is defaulting to the lower letoff percentage.

So, if you explicitly input "65" in the percent letoff box

either in the Equipment Tab
(database selections) page of OT2,

or if you explicity input "65" as the percent letoff
in the Equipment Tab (My Setup) page of OT2,
(upper left corner under Bow Measurements)
then

yes....the setup shows stiff.


However, if you go to the Equipment Tab (My Setup) page of OT2,
and explicity input "80" as the percent letoff
in the Equipment Tab (My Setup) page of OT2,
(upper left corner under Bow Measurements)

then the spine indicator moves to the "weak side" of the green zone.


So, it kinda depends on the percent letoff module
on the Ross CR337.

I assumed the bow has a 80% let off module.

This assumption is based on the "odd tear" he is seeing
when shooting through paper.

Let's see what we find out.

We are missing a key piece of information.

 

[Tailhunter]

Did some more tinkering today .. cut current shaft back to 28", left everything the same. Perfect bullet hole. This tells me that the shaft was a little light in the spine. I think that 68lbs. and a 120 gr head would make it rip a big one ......

Nuts and Bolts ...
Not really wanting to lower the poundage .... can you give me a correct arrow and tip for the current 65 lbs...... and yes it is 80%

Thanks......

 

[nuts&bolts]

Here are a few options

Did some more tinkering today .. cut current shaft back to 28", left everything the same. Perfect bullet hole. This tells me that the shaft was a little light in the spine. I think that 68lbs. and a 120 gr head would make it rip a big one ......

Nuts and Bolts ...
Not really wanting to lower the poundage .... can you give me a correct arrow and tip for the current 65 lbs...... and yes it is 80%

Thanks......

Carbon Express CX Edge Hunter 350 shaft
cut the shaft to 28.5"
(not including the nock or insert length)

Use a full sheet arrow wrap (weighs 10 grains)

Use 2" Blazer vanes

Use your 85 grain broadheads

Velocity = 265 fps
7.161 grains per lb

FOC = 5.64 %
72.50 lbs of KE






Carbon Express Maxima Hunter 350 shaft
cut the shaft to 28.5"
(not including the nock or insert length)

Use a full sheet arrow wrap (weighs 10 grains)

Use VaneTec V-Max 4" vanes
(these larger, heavier vanes will make the shaft behave stiffer)

Use your 85 grain broadheads

Velocity = 280 fps
6.088 grains per lb

WOW!!

FOC = 6.33 %
68.82 lbs of KE

 

[Tailhunter]

Got any ideas on the Goldtip ... 55/75 or probably the 75/95 ... could you let me know. Also, what do you use on your string to silence it for hunting? Thanks....:darkbeer: