Tuning carbons - need help

[Mitch-In-NJ]

I purchased a lighter bow (43#) earlier this year and figured I would try carbons.  I like them so I decided to try some on my primary bow which is 55#.  I can get 5575s to fly pretty good, but they are very light.  About 485gr.

My setup is a Stewart Slammer 55# @ 28".  My draw is 29.5".  The Slammer is cut to center and with the side plate maybe +1/16 shy of center.

Up front I wanted 125gr. BHs with 70gr. insert weights - the GT ones that screw into the back of the aluminum insert.  I had to cut the arrows to 30" and drop down to 50 gr. inserts and they still show a little weak when bare shafted but they fly really well fletched.

But I am used to a heavier arrow, so I bought some 7595s.  Thought I could load up the front to get good flight.  What I found is that with a 200gr. field point and 200gr. of inserts full cut 7595s weighted in at 852gr. and were still showing a bit stiff.  But holy cow do they punch thru a target.

I have a Morrell bag target that I keep behind a Glendell Buck and these things punched thru the buck and all the way to the back side of the Morrell.

But, they are full length with 400gr. up front and still show as stiff.  I am not sure I even want to go with 400gr. up front, much less add even more weight and I prefer my arrows be cut to 31", not 32".

So, here are my questions:

Should I just be happy with the light 5575s?

OR...

Will using 100gr. inserts with 100gr. broadhead adapters and either Big Jim's 250gr. or Woodsman 190gr. broadheads make the spine weaker than putting 200gr. behind the aluminum insert and still using one of the previously mentioned broadheads?

AND... is 825gr. getting just a bit absurd?

BTW - Stu's calculator shows the spine on the 7595s setup as stated above at 36#.  My form isn't perfect but it's not THAT bad.

Thanks.

[Steve O]

Maybe try a thinner sideplate?  Teflon tape?

[stickhead]

How about three rivers weight tubes

[JimB]

I'm really confused,.

First,when I go from 5575 arrows to 7595's,my 7595 arrow ends up being about 130 grs heavier than the 5575.

In your 2 setups,the difference is 367 grains.Something doesn't sound right.

My 7595's are black shafts,not woodgrain and are 2" shorter than yours at 30".They have 5" fletch,a 12 gr cap wrap and a 6 gr nock end footing.On the front end 400 grs.With all that,they weigh 709 grs.

Your arrows are 2" longer and weigh 116 grs more?How is that?Woodgrain finish could amount for 30 grs.,2" could amount to another 20.It still doesn't add up.What did you do to get your arrows that heavy?

If you use woodgrain finished arrows,you can drop 30 grs right there plus up your FOC but check your math.I can't make that work for me.

[Hookeye]

Or do like I did and cut the sight window deeper  

IIRC Blackwidows on the SA series, are 3/16 past center, so with a velcro type sideplate they ran (my two at 55 and 57# @28") GT55/75's just fine.

30.5" with 50 gr added up front, 125 gr tip.

Same arrows showed way stiff on my Samick Phantom but it was only cut to center. Hogged that out and it shot fine.

My current Tradtech was only cut to center, and only 50#. There I got good bareshafting with GT35/55's with 50 up front and a 125. I took the riser in some, then some more, to make it closer to centershot.

Had to remove the added weights to get the spine right. Had to drop # to 46 too. Next experiment will be clipping 1" off and see how much that stiffens em up.

My form must suck, or something, but it takes 1" of measurment and 50 grains for me to see anything noticeable, from my above bows/testing.

55@ 489 grainers from my BW's hit right at 200 FPS and I blew through 5 of 6 deer (small data set but still a data set). Only one that didn't was a straight down spiner, and the Snuffer tip was out the other side of the vert.

So...........I think 480's trucking around 200 to be quite usable. Not sure about lighter/slower.

No data collection at this time.

[Mitch-In-NJ]

JimB - the 5575s have a 50gr insert and a 125gr point.  The 7595s have 200gr insert and 200gr point.

485 - 5575s
225 - additional weight
130 - measured difference between 5575s and 7595s
840 - total new arrow weight (give or take)

Thanks to everyone who replied.  I appreciate the suggestions.  I have considered each of those ideas.  

I am still especially interested in knowing if using a 100gr insert with a 100gr glue on adapter will give me more flex than 200gr behind the aluminum screw in adapter.  My thinking is that it might as the weight is slightly more forward.  I just don't have any of that hardware and if anyone has any input I'd appreciate it.

Also, am I getting into the realm of the absurd with that much weight?

Again, thanks to all who replied.

[Steve O]

I think the further you put the weight out toward the point, the more effect it will have.  Think teeter-totter.  With that said, I don't think any of us here is a good enough shot to be able to tell the difference, no matter how good they think they are    

And yes, you are getting to the ridiculous level of FOC...

Think about it; what if anything in our everyday life works BEST at the extremes? You don't usually drive a bicycle or a NASCAR to work, right?

[Mitch-In-NJ]

Looks like I will be going back to aluminum.  Maybe after the season I will try carbons again.  It seems that the 5575s are too weak and the 7595s are too stiff.  I will see if there is something in between from another manufacturer.

Thanks for the input.