Sitka Mountain Gear
Bare Shaft Tuning Issue??
Equipment
Contributors to this thread:
Bowbender 06-Jun-18
ohiohunter 06-Jun-18
Hawkeye 06-Jun-18
WV Mountaineer 06-Jun-18
trkyslr 06-Jun-18
Russ Koon 06-Jun-18
RogBow 06-Jun-18
hardcore247 06-Jun-18
Bowbender 06-Jun-18
bigdog21 06-Jun-18
Rutnrod1995 07-Jun-18
4blade 07-Jun-18
ELKMAN 09-Jun-18
Shawn 09-Jun-18
Bowbender 09-Jun-18
Russell 09-Jun-18
From: Bowbender
06-Jun-18

Bowbender's embedded Photo
Bowbender's embedded Photo
Ok, back in April I picked up a Hoyt HyperForce. 62 lbs, 28-1/2" draw. Arrows are Easton Axis 400's, 29" long with 100 grain tips.

I've been shooting several times a week and really like the bow. Dead in the hand, quiet and fairly quick. Was off today and decided to see how my boradheads fly. Slick Trick Standards, 100 grain. They were hitting right and somewhat low at 20 yards. Plus arrow flight was not what I would call good. So, I went and got two bare shafts and shot. Holy crap!!!! The bare shafts are hitting 4-5" to the right. Arrow flight was terrible. I looked like the nock end was spiraling in. I dropped the draw weight one full turn and same thing, except the arrows hit lower. Several times it looked like the arrow was going to hit sideways.

When I bought the bow,I asked the tech if the 400's were spined adequately. He assured me they would be fine. I 'm guessing they are underspined. Looking at Eastons new chart it;s calling for a 340. I know a few years ago when I checked 400's were ok for my Mathews LX with the same specs. Noticed a few other issues like my peep keeps moving and when I left the pro shop I was at level knock, now it's very nock high when the rest is in position.

Thoughts?

From: ohiohunter
06-Jun-18
Your strings have stretched, that'd be my first issue to address. Either twist them up back to spec or replace, tune, then test your results. If issues persist most likely spine.

From: Hawkeye
06-Jun-18
Definitely get your nock back to level and shoot a couple more. Fix that first and make sure your synchronization is perfect (cams hitting at the same time)

Eventually I think youll have to twist the left yolk and take a couple out of the right.

06-Jun-18
Above x 2.

From: trkyslr
06-Jun-18
I shoot more poundage then you (#74) but my arrows are 28.5” long and I shoot 300 spine.. 400 does seem weak to me since your arrows are 29” long even with a lower draw weight.

From: Russ Koon
06-Jun-18
Strings may have stretched, but I suspect your center serving may also have moved if your nock has moved as much as you indicate. In either case, definitely need to fix the string problem and bring the bow back to the settings it was designed for, first,THEN tune, and readjust the sights as your final step after estabishig good groups and tuning for BH impact to be same as FP.

You didn't mention what rest you're using. The Whisker Biscuit is probably the most popular rest in use, and I love mine and have used them for many years, but one thing about them you might want to keep in mind is that any of the 'full capture' rests tend to be difficult to tune using the bare shaft technique. I used that as my primary tuning method for years before switching to the WB, and fought the tuning issues for a good while afterwards. Tuning the arrow flight is still the same process and tuning for BH and FP impact to be same is still the way to go, but the results of bare shaft tuning can be misleading with full capture rests. I found that I was much better served by eliminating that tuning method and proceeding directly from getting a good visual flight, especially with a lighted nock which really shows any porposing or tail-wagging, to bringing the BH impact point in agreement with the FP one. When you've achieved that at forty yards, you're good to go, tuning-wise. The bare shafts may or may not agree, but the result you're really after will be there.

I'm not sure of the reason for it, but I suspect it is some very slight torquing of the bow that is magnified by the rest imparting that influence more to the arrow because of the fact that it is in contact much longer.

If you use a D-loop, that could also slipping up the string and changing the nocking point.

It does sound like you may be underspined, but the string issue needs to be taken care of before any other decisions are made. I got by shooting 400's through my LX at nearly that poundage and got good groups, but I always liked arrows on the stiff side of those recommended in the charts, and was happier with my consistency with 340's.

From: RogBow
06-Jun-18
What Hawkeye said but first check string and cables for wear and correct length.

From: hardcore247
06-Jun-18
Try yoke tuning to get fletched and bare shafts to hit in the same spot. It worked on my defiant. It also got my Broadheads and field points hitting together.

From: Bowbender
06-Jun-18
Guys,

Thanks for the input. Definitely plan on getting the string issue resolved prior to doing anything. Really surprised that I would get that much stretch after two months of less than average shooting. Especially on an $1100 bow. I had the strings replaced on my LX two years ago, they haven't budged.

Russ, I'm currently shooting a QAD rest. Never saw such poor bare shaft flight in my life. I don't "think" torque is the issue. Bow has nice thin grip that just lays perfectly in sweet spot in my hand.

From: bigdog21
06-Jun-18
340

From: Rutnrod1995
07-Jun-18
Perhaps underspined a bit? That would be what I would check. .400 seems awful light. I had a similar issue and moved up a spine. Seems to have solved the issue. Good Luck!

From: 4blade
07-Jun-18
I shoot 340's outta all my 60lb bows. By one bare shaft and try it.

From: ELKMAN
09-Jun-18
The 400 spine is fine if he would have cut them the right length. (28") But you are still fine at that poundage at 29". You need to put some twists on your left yoke and take some out on the right. Also check your nock/loop height. (Move it down)

From: Shawn
09-Jun-18
I agree with Elkman if you can cut them down a bit you will be fine. I shoot .400 spine and shoot 66#s with 190 grains of point weight but I draw 27.5"s and shoot a 27" arrow. Stiffens them plenty at that short. Shawn

From: Bowbender
09-Jun-18
I went to LAS this morning. Tech and I went back to the range to watch me shoot. He also shot it as well. First thing he noticed was the cam timing was off. Took care of that. Got the nock height squared away as well served in the peep. Bare shafts are hitting right with the field points. He did mention that I may be underspined but said go home shoot some more, try your broadheads and see where they are hitting. If there is still an issue, come back and we'll get set up with 340 spine.

Just cheap plug for LAS. When I bought the bow in April it was set up with an Axcel ArmourTech HD 4 pin sight. I just didn't like it from the start. Sight ring was not bright, nor were the pins. And I hated the single line on the level. I like two lines to center the bubble. Sight was built like a tank and adjustability was great, I just didn't like it. He asked which one I did like. I had wanted to get the MBG Widowmaker and stated such. Took my bow and switched them out. Got he 20 yard pin dialed in. I was feeling pretty happy by now. Bow is shooting great, lovin' the new sight. I go to leave and he tells me they owe me the difference in price on the sights. Certainly didn't expect that. I expected to eat the difference which was $45. Nope. They credited back to me. LAS's customer service is second to none.

From: Russell
09-Jun-18
That sounds great! Nothing like honest people.

Suggest buying a bow press and learning to do your own work.

I did that a few years ago and very glad I did.

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