Carbon tuning expert?

[Biathlonman]

So I'm getting perfect bullet holes at 30.5" Gt5575 and 145 gr. Point.  Problem is I have a crap load of 175gr. Points and. Broadheads.  So how much do I trim?  Any guesstimates or should I just head to the classifieds and hope to swap?

[Dan Adair]

IIRC, you're using 100 grain brassies for inserts?

I have a bunch of 50 grainers, I could mail you one  

[PaddyMac]

Before I trimmed, I would add 7" of crest wrap. In my experience that's good for about 25 grains ± on a 5575. A fourth feather will also stiffen them up a tad. And then when you get to trimming, trim only 1/4" at a time. The biggest factor I've found in GTs is length, tho.

I just fletched a half dozen 3555s just now that are darts in my longbow with 145s with wraps, and without wraps same thing with 125 gr. But I have a gazillion 5575s all topped with 175s for my recurve.  I really wanted to shoot 5575s w/ 175s in my longbow, but not to be.    

[Biathlonman]

Not With this set up, just the standard alumnium

[floodman]

Screw Them 175 Grains in and put some twist in your string,and that will stiffin the spine of your shafts,only 30 grains off,Maybe go with diffrent silencers...You can do it Man..Or I have a really Nice 59er That shoots anything  :D

[PaddyMac]

I couldn't get the 3555s long enough to shoot 175s and I couldn't get my 30.5" 5575s weak enough, even with 250 grains, to fly right in my longbow. They seemed to spine right, but just horribly inconsistent. So I'm just looking at my field points... over a hundred 175 grains and how many 145s? Five.  And, they're 11/32ths  

[Biathlonman]

Hadn't thought about the wrap and fourt feather option, that might just work and is my preferred anyhow.

[Biathlonman]

Now I've got myself confused.  Weight on the back stiffen or weaken the arrow?

[PaddyMac]

Weight on back stiffens, but there is also just the structural stiffening of the vinyl. I discovered this bare shafting.  On a 5575, a 175 gr. on a wrapped shaft performed exactly like an unwrapped with a 200 gr. I was able to duplicate it 200/225 and 225/250.

[PaddyMac]

Wait, I have that backwards. The 200 on the wrapped performed exactly like a 175 on an unwrapped shaft.    

[floodman]

Dont forget about the drag a feather puts on a arrow which can weaken,this can be confusing,because the feather when shot out of a bow lays down,stiff..then down range the feather raise up which causes drag weak  then,,Saw this years ago on a slow mo video,back when I was a archery rep,and had my Pro Shop,Less all Go out and buy Sling Shots,It is instictive,and the ammo is Cheap...

[JimB]

Before you do anything,why don't you build your side plate out app.1/16" .That probably will be enough to add 30 grs of point weight.

[Brad Arnett]

If you "need" some 145's I can help you out. I have a crapload of 145's and need some heavier stuff.