How important is shaft straightness for hunting??
02-18-2005, 04:48 AM
#71
Join Date: Feb 2003
Location:
Posts: 2,413
RE: How important is shaft straighness for hunting??
I've had more troubles grouping broadheads due to spine problems over anything else. In my opinion the spine ratings on ICS carbon arrows are too generalized.
I have managed to get great broadhead flight from my arrow building. My procedure to build an arrow is the following: Select a shaft that is slightly too stiff for the cam and poundage I'm shooting. I then cut from both ends at 90 degrees. I spine test, marking the stiffest side with a marker. I cull any arrows falling below a particular spine (too weak). I then align the cock feather with my mark. This way, each arrow has the stiffest side flexing the same way. Then, I attach feathers with a strong helical to get the arrows spinning and attach a broadhead heavy enough that I get an F.O.C. of at leat 10%. With this method I've gotten great flight from even cheap arrows. The difference is the number of arrows I keep out of a dozen. I've increased my percentage of "keepers" from all dozens, but the more expensive arrows (at least from some brands), have yeilded higher numbers of "keepers". This is the reason I have found them to be worth the price to me.
02-18-2005, 07:41 AM
#72
Join Date: Feb 2003
Location: SC USA
Posts: 1,434
RE: How important is shaft straighness for hunting??
The difference is the number of arrows I keep out of a dozen. I've increased my percentage of "keepers" from all dozens, but the more expensive arrows (at least from some brands), have yeilded higher numbers of "keepers". This is the reason I have found them to be worth the price to me.
02-20-2005, 09:53 PM
#75
Join Date: Feb 2003
Location: Central Louisiana
Posts: 144
RE: How important is shaft straighness for hunting??
Most dozens will show at least a .030 difference between the stiffest and weakest arrow in a group (that's a lot). I've measured some dozens where the vaiation was .065. That's incredibly huge variation, that can't possibly result in a consistant shooting dozen. If you're shooting borderline spined arrows, you are not likely to get the same point of impact from such variation, when shooting broadheads.
It would be very helpful and informative to know just what the measured difference in point of impact was that you have found with these variations in spine deflection. Also did you find a pattern in point of impact differences to spine difference (weaker spine high, low, left or right)?
Also one thing that I don't believe I have seen mentioned in this discussion that has been the biggest determining factor for me in broadhead grouping is alignment of insert to shaft. I have my own system of installing inserts that works for me and I hate to let anyone else install inserts on arrows for me to shoot. I have shot arrows with fixed broads only to have them fly all over the place, then remove the insert and install straight and have the same arrow fly perfectly. This has occured with some of the best and worst straightness tolerance and and highest and lowest priced arrows.
02-21-2005, 02:20 AM
#76
Thread Starter
Join Date: Feb 2005
Location:
Posts: 178
RE: How important is shaft straighness for hunting??
have my own system of installing inserts that works for me and I hate to let anyone else install inserts on arrows for me to shoot.
02-21-2005, 05:07 AM
#77
Join Date: Feb 2003
Location:
Posts: 2,413
RE: How important is shaft straighness for hunting??
It would be very helpful and informative to know just what the measured difference in point of impact was that you have found with these variations in spine deflection. Also did you find a pattern in point of impact differences to spine difference (weaker spine high, low, left or right)?
02-21-2005, 05:56 AM
#78
Nontypical Buck
Join Date: Feb 2003
Location: CT, USA
Posts: 3,058
RE: How important is shaft straighness for hunting??
ORIGINAL: Straightarrow
Ever since I've built my spine tester, I've been a bit amazed at the variation in spine among a dozen carbons. Most dozens will show at least a .030 difference between the stiffest and weakest arrow in a group.... I've measured some dozens where the vaiation was .065. That's incredibly huge variation, that can't possibly result in a consistant shooting dozen. If you're shooting borderline spined arrows, you are not likely to get the same point of impact from such variation, when shooting broadheads. I have found certain brands to be less consistent than others and have found the lower tolerance for-straightness arrrows to be less consistant than the higher end ones in most cases. This makes sense that a straighter arrow is also likely to test more consistant with spine. Aluminums shoot so good, because they are not only very straight, they are very consistant with spine. Seldom can I measure more than a .005 difference in a dozen.
Ever since I've built my spine tester, I've been a bit amazed at the variation in spine among a dozen carbons. Most dozens will show at least a .030 difference between the stiffest and weakest arrow in a group.... I've measured some dozens where the vaiation was .065. That's incredibly huge variation, that can't possibly result in a consistant shooting dozen. If you're shooting borderline spined arrows, you are not likely to get the same point of impact from such variation, when shooting broadheads. I have found certain brands to be less consistent than others and have found the lower tolerance for-straightness arrrows to be less consistant than the higher end ones in most cases. This makes sense that a straighter arrow is also likely to test more consistant with spine. Aluminums shoot so good, because they are not only very straight, they are very consistant with spine. Seldom can I measure more than a .005 difference in a dozen.
I'm curious how many people who are not worried about cheap carbons would tune your bow up for XX78 2314's, and then shoot a mix of 2314's, 2315s, 2413s, and 2219s out of it?
That's essentially what you are doing if you shoot a dozen carbons shafts which vary up to .065 in spine...
02-21-2005, 06:04 AM
#79
Join Date: Feb 2003
Location:
Posts: 2,413
RE: How important is shaft straighness for hunting??
That's essentially what you are doing if you shoot a dozen carbons shafts which vary up to .065 in spine...
02-21-2005, 06:53 AM
#80
Typical Buck
Join Date: Feb 2003
Location: Northern IL&Southern IL
Posts: 963
RE: How important is shaft straighness for hunting??
I used to be a machinist years ago and some of the parts that we inspected we did a concentricity test on a metal shaft just 4" long.If the shaft was even .003"of an inch it was rejected.Now just think;three thousands of an inch of a four inch span compared to an arrow shaft that is at least 25"thats an awfull large error.Spin test any arrow with a broadhead at the end ,on a streight arrow with an "even" glue line, and you can even see some wobble wich could be from other factors other than the shaft .I would get the straightest arrows possible or that I could afford,You do get what you pay for most of the time.Hey and in archery or any target sport isn't accuracy paramount?Hunting too!