Weird tuning question

[Dave Grover]

I did some bare-shaft tuning with a Traditional Only carbon kit cut to 29" on my 45# Samick Sage about six weeks ago.  I put a fast-flite string on it, let it stretch for a week, and set the brace to about 8.5".  I did my level best to get heavy arrows and heavy field points.  But I ended up with 9.1gpi or 400spine/125gr points, and they shoot just fine.  I get consistent groups and 125gr 2-blade broadheads do just as well.

But that's not my question.

My wife thought this looked like a lot of fun so she went out and got a 40# Samick Nighthawk.  (2x+ the cost of mine, but whatever.)  We stretched the string it came with for a couple of days and tried some bare-shaft tuning earlier this week.  The Nighthawk is a beautiful bow, with a bigger riser, wider limbs, and its 60" instead of the Sage's 62".  We started with 400/125gr, thinking she'd be close to my arrow.  But she's not.  This bow likes 340 spine/200gr points, and seems like it could go heavier.  She's drawing 28", anchoring consistently, and shooting my fletched arrows pretty consistently.  Being a guy I thought perhaps she was just doin' it wrong so I shots some arrows myself, and sure enough I get a straight-on arrow at 10 yards with 300-340 spine carbons and 200gr points.

This is very counterintuitive: A lighter bow seems like it should shoot lighter arrows.  But I'm new at this, and I've only tuned the Sage (and my daughter's 25# version).  Anyone have any experience with this?  I put a fast-flite string on it today and we'll let it stretch this week and try tuning again next weekend.  But I'd appreciate some confirmation one way or the other.

[Mitch Edwards]

First off I'm no expert had a lot of tuning problems lately with carbons (was a wood guy). My only real guess would be that your wife's bow is cut further past center than yours but 340s from a 40# bow? That's crazy cause I'm working on 340s for a 60# bow. Lots of factors I guess. I'm sure someone will know far more than I

[Pine]

No two bows are alike .
I have a 55# bow that shoots the same arrow that my 43# bow does .
I also have a 45# bow that shoots an arrow 15# heaver than it should .
That's why they call it tuning , each bow is an individual .

[damascusdave]

I like the way my friend Cameron puts it "bow like what they like" and Cameron has tuned more bows that most people will see in a lifetime...he changes bows more often than he changes his underwear

DDave

[Rough Run]

I have a Samick Phantom.  Had a similar experience, with arrows needing to be stiffer than expected, or other bows, except that I don't bare shaft.  More so with the POC shafts.  Then again, only less so, when I switched to FF string from B-55.  I made adjustments to the brace height, nock point & shelf, and that settled down the arrow flight.  My arrows are 30.5" bop.

[PaulDeadringer29]

You might be so far overspined with both bows that you're getting false readings.

I just don't think a .340 arrow would shoot better from a 40# bow than a .600 (or even .500) arrow would....especially being carbon arrows.

[savagelh]

I shoot 400's with 125gr heads out of my 45# bow too. 340's out of a 40# bow sounds stiff but bare shafts don't lie.

[Bladepeek]

Arrows sound way too stiff on both bows.

If you're getting good flight from them, then you're good, but arrows would have to be 600 spine for me to shoot them out of any of my mid-40 bows at that length and point weight.

Just out of curiosity, have you compared bareshaft and fletched for the same point of impact?

[Shadowhnter]

I dont know about carbon, but in woods a 75gr jump would make a difference in spine needs, esp going from roughly 100gr to 200gr, even considering the supposed 5 lb draw difference. ...which is another issue. Samicks arent often marked accurate, and you need to know the bows actual draw weights. Its possible that yours being marked 45lb could be as low as 43lb or even less, and hers could be as high as 45-46lb. The industry standard is within 5 lbs of what its marked, but we have 3 samicks and none are as marked. However all 3 are actually heavier then marked.

[Dave Grover]

I never considered the actual draw weight; I'll give that a try.  The Nighthawk has a longer riser and shorter limbs, so it would stand to reason its just a stiffer bow even if its labeled 40#.  It may be its 40# at 28", but its mechanically going to have to recoil at a faster rate than the Sage because of the riser and the shorter limbs.

I've tried underspining.  I tried every arrow in the kit, starting with 600/100gr points.  I couldn't get anything to nock left except for the 340s.  I'll let the string and the bow settle in for a bit before I try it again.

The bare shafts are shooting to the right of the fletched arrows.  I'm using 400/125gr for fletched; I don't have a lot of range of fletched.  I can try a 500/100gr fletched to see what I can get.

Thanks for the responses!

[bucknut]

I would say the 500"s with 200 tips would be very close for both of you.

[Bladepeek]

I would still suggest shooting a couple bareshaft and some fletched at 20 yds and see where each impacts. If the bareshaft don't hit to the left of the fletched (assuming you're right handed) I'll be amazed.

[mahantango]

This is kind of unusual as those arrows are way stiff. Are you both shooting right handed? I shoot .600 out of my 40-50# bows and .500 out of 50-60# bows. Unless you are pretty experienced archers with really good form and release, bare shaft tuning can be a crap shoot.

[arrowlauncherdj]

Really depends on how far past center your shelf is cut. I shoot 7595  trads .300 spine cut to 30.5" with total 225 gr up front and everyone says I'm overspined. I think everyone else is under spined haha. I have tried every arrow and point combo out there and thats the only thing I can shoot straight. Bare shaft to 30 yds just fine shooting 2 under 58lb home made recurve 60" bow. It's a speedster tho. I am cut 1/8" past center. If it works it works.

[crazynate]

Bows like what they like. If they are hitting where you want them too who cares what spine they are