Well, I've just about given up trying to tune these 100 gr slick trick magnums with my Obsession Evolution. Consistently hitting 3-6" left at 30 yds. Shooting GT XT Hunters, 5575/400 spine, 27". Field points are pretty much dead on (I walk back tuned with them), but when I tried moving the rest to the right (yes, in very, very small increments) to bring the ST's back in, there was no change. Got to the point where it was obvious to the naked eye that the rest was too far to the right...ST's still hit left...so I put it back to where it was.

I've spun the arrows, changed BH to another arrow (same type) all with same results. No arrow/rest contact either. I know, I know, it's most likely my grip or form, but then again I try different things with the grip in between shots and they are still grouping together tight (but still 3-6" left of POA). I don't really want to move my sight out to the left because I feel it's just masking the problem.

Only thing I haven't tried is a weaker spined arrow...I remember seeing a chart that said BH's hitting left means arrow might be too stiff. Is it possible with 60lbs, 28" DL, 27" that the 400 spine is too stiff? Anything else I may have missed? Any other tuning that can be done to the bow?




2014 Obsession Evolution, 60/28, Stormy Hardwoods Gunmetal, Red cams
QAD HDX
Spot Hogg Tommy Hogg
Scott Silverhorn
10" Beestinger

400 spine sounds very stiff for 60lbs @ 27"

I've never had to adjust my sights or rest when going from field tips to broadhead. You sure there's not a slight wobble to your arrow/broadhead setup? Did you spin them in your hand?

hmmm...according to GT's arrow chart, it should be right on the money. This, and the pro shop assured me this was the right spine for my setup.

Having said that, I'm open to trying a weaker shaft.

I'm no expert, but u could try a 300.

Yes. I don't have one of the fancy "arrow spinners", but I did spin it like a top, as well as rolled the arrow on a flat surface and no wobble. Watched the guy at my pro shop cut the arrows and square them, so I feel confident this isn't the problem. Also swapped out arrows and BH's couple of times with same results.

One thing I just discovered (on recommendation from a friend) was that my ATA and brace height were a little off. ATA was 32 3/8" (spec is 32"), and brace was 5 7/8" (spec 6"). I wonder if this could be a contributing cause

I would think that your field tips wouldn't fly correctly, if the ATA and brace height were the problem. Sometimes I have to tighten or loosen my broadhead to get it to spin smoothly in my hand. If yours spin in your hand without any felt wobble, then I don't know what your problem is. Sorry I can't help you. Good luck.

[/quote]I would think that your field tips wouldn't fly correctly, if the ATA and brace height were the problem. Sometimes I have to tighten or loosen my broadhead to get it to spin smoothly in my hand. If yours spin in your hand without any felt wobble, then I don't know what your problem is. Sorry I can't help you. Good luck. [/quote]


You know that's a great point! Didn't think of that. I guess i'll go back and get maybe a 500 and a 340 spine arrow and see what happens

I would think that your field tips wouldn't fly correctly, if the ATA and brace height were the problem. Sometimes I have to tighten or loosen my broadhead to get it to spin smoothly in my hand. If yours spin in your hand without any felt wobble, then I don't know what your problem is. Sorry I can't help you. Good luck. [/quote]


You know that's a great point! Didn't think of that. I guess i'll go back and get maybe a 500 and a 340 spine arrow and see what happens [/quote]


Btw, I shoot a 5575 GT Expedition Hunter out of my Hoyt 65lbs @ 28.5".

Have u shot through paper? If so how did the tear look?

No, not yet anyway

Hitting to the left indicates weak spine, but a 400 spine should be perfect for your set up though. Give this a try and see if it helps. You don't have to hang a string, you can just draw a vertical line and use it. When you're done try the broadheads vs. the field tips again.

Also are you left or right handed?

Right handed.

Thanks for the chart. Looks like step 4 and 5 were cut off at the bottom though. I'll try this over the weekend

oops...never mind! I see them now

Did you get it fixed?

I like this Shaw. I just put a QAD Ultra on my Switchback , I think I'm gonna give this a try.

Not yet...taking it to the shop mon or tues. and have him check everything. I'll post when I find something out.

10-fo. Just curious.

I would try a stiffer arrow on that evolution....I don't know why, but every bow that guy designs requires a stiffer arrow than what the charts say.