Hey guys and gals just wanted to point out that since I've switched to 145 field points my GT 600's are flying tons better out of my bear grizzly 45# I was shooting a 125 point but seems like the flight was a little erratic here and there. I recently purchased some zwickey 150 grain heads and figured I needed to go with a close match gn to get the feel. Any explanations as to why all of a sudden my groups have tightened up with the 145 points and fly better I'm pleased with the results but was curious about the science behind what happened.
Uh, maybe because you got the spine closer to being correct???
I have 600 GT Trads 100 grain brass inserts total Arrow weight is coming in around 510 grains with the 145 points
The science behind moving the balance point forward on an arrow has been available for more than ten years: Understanding and Applying FOC (http://www.alaskabowhunting.com/PR/Ashby_EFOC.pdf) by Dr. Ed Ashby.
ALL THINGS BEING EQUAL, moving the balance point forward will improve flight and thus penetration. It's the failure to change only a single variable (in this case the distribution of total weight along the length of the arrow) that gives rise to a lot of the misunderstanding and hoo-hah that pops up concerning this aspect of the Ashby studies.
In this case, you would need to build arrows with slightly different spines in order to isolate the effect of moving the balance point forward by using a heavier point. Or you could just keep on shooting what works (better) for you. :archer2:
I do think heavier arrows are inherently more stable possibly because they are traveling slower and less affected by the air. But as others have mentioned it may be that these have your heads are getting your closer in spine to where you need to be.
Thanks for the helpful info understanding the reason behind it thanks again
Sounds to me like You got the dynamic spine closer to where it needs to be with the heavier head.
It's not just the heavier weight, it's where you put the weight. As others have noted, adding point weight decreased the dynamic spine and brought the arrow in closer tune to your bow.
The science behind what happened could be illustrated if you would shoot bare shafts with the two different points, and see which flew straighter. By comparing the angles the bare shafts made with the target, you would have an objective measurement of which combination was better tuned for your bow, as opposed to a subjective feeling that one combination was working better than another.
I'm just happy to hear that you found something that works for you. It's always fun when it comes together.
-Jeremy :thumbsup:
Because your arrows were not tuned well with the 125gr points, but apparently are tuned better with the 145gr points!
Bisch
OkieBowHunter11,
Where in OK are you? There might be someone near you that could meet with you in-person and help you out with whatever questions you may have...
Just a thought.
And I aree with what most of these guys are saying, in that, you are probably tuned a little better with that point/shaft combination than you were with the lighter point. Glad that it's working better for you.
-Tony
Yessir as tony said hit either of us up if you ever want help in person!
QuoteOriginally posted by Fattony77:
OkieBowHunter11,
Where in OK are you? There might be someone near you that could meet with you in-person and help you out with whatever questions you may have...
Just a thought.
And I aree with what most of these guys are saying, in that, you are probably tuned a little better with that point/shaft combination than you were with the lighter point. Glad that it's working better for you.
I'm here in muskogee Tony I work through the week and I'm free on the weekend there is a unmarked 3d shoot in wagoner coming up this month I believe the weekend of the 17th of may would love to meet you guys anytime for sure and thanks
-Tony
Holy cow....you guys are neighbors. Tony is good people!!
Sending you a PM, Okie.
Thanks, Skitch. I wish you were still around here, bud.
No, more grains does not always equal better arrow flight , if that were the case we would all have bowling balls on the end of our arrows which is ridiculous.
I don't care who's study you read (lots of folks have their own studied that are unpublished studies) it may help in your situation but others it may not.... more grains again does not equal better arrow flight as I replied. End of story and I'm not a doctor and neither is .....
Sorry for screwing up first post.
I also have a Bear grizzly 45#. A friend helped me tune it wit GT 1535. Ended up with the aluminum inserts and 175 grain field points. The grizzly shoots them pretty fast and straight. I put on my Simmons broadhead 175 gr Shot just as good. I used those same arrows in my bear Montana 50#, and they shot just as straight.
Tune the arrow to the bow to the shooter. I personally like heavy foc arrows in the 10gpp range. It's all about the tune.
Agreed I feel like this solution has help me find and get closer to correct spine and makes me that much more confident I shoot the 125 points ok don't get me wrong but I shoot the 145s better. I can tell the arrow is flying better without watching it's flight just picking a spot and following through shooting instinctive.
I agree with heavier does not mean better arrow flight.
I use only 165 total grains up front (point and insert) on some 600's for my 45 lb go to recurve. Can go down in point weight 20 grains or up about the same and still get a very acceptable arrow flight. Most comfortable arrow flights for me are 165 to 175 grains total up front.
Interresting points here. I shoot GT 600 my self with 52gr inserts and 125gr field points out of my 37# Cayuga. My arrows are full length at 30,5" and fly reasonably well. Maybe I should try putting more weight up front?
Way back when, before people were having penetration problems on whitetail deer, when Acme cedars, Microflite and 1918 aluminum arrows were normal, a lot of excess head weight was not a desirable thing. That 125 grain head weight was agreed on as being just about right for almost everyone, but if you had a heavy bow you could always go for those over kill heads, a four blade Delta or a Herters or heaven forbid a Deadhead. We even preferred swaged aluminums to get the point weight down. With there only being three basic spines to pick from with carbon shafts, I understand all of the messing around and experimenting, and all of the threads talking about how to get them to behave. For those of us that use the arrow length as a draw check device, carbons are an increased complication. I tried some 190 grain heads on Surewood arrows that the charts say are over spined with 160 grain heads. No way, I am cutting those Ribtec 190s down to be Ribtec Hills.
with an arrow saw a few spine choices.
then bare shaft and paper tune,and a good arrow saw you can get an arrow to fly with anything you want to use. my move to heave FOC was due to the lack of grain weights of carbons when I was shooting my 80lb bamabow tribute. unless I wanted to go Easton FMJ DG and push heavier than I wanted arrows I had to experiment. my goal was 9.5-11gpp I managed to hit right near 10gpp.
After that time learning how to tune I found that I liked the way my arrows flew, hit and felt. They run right about 10gpp now and zoom. I droped poundage to a 58lb McBroom. and went from a 300 spine to a 400 spine GT velocity.still at that 10gpp range with 585grain arrows with about 28% foc. no mater what you do it comes down to a perfectly tuned arrow matched to the bow, with the shooter shooting their best.
Putting a broadhead on your arrow will let you know if you're arrow is tuned real quick.
As the saying goes, too much of anything is not good. I try to find a balance w my 42 pound whip that is used for hunting, stumping, and 3d. Bareshafting determines my point weight w full length 600 gts or bemans. This happens to be 200 grs. This works GREAT on our big white tails and I don't shoot over 20 yes in my hunting situations so having an arrow approaching 14 gpp works for me. Now if I was really trying to get every edge I could in 3d I'd flatten my trajectory by going to a lighter spine arrow which should allow me to reach tune w less weight up front and have a lighter overall arrow. Once you develop solid form your bow will tell you what weight up front is ideal. Best of luck.
QuoteOriginally posted by McDave:
The science behind what happened could be illustrated if you would shoot bare shafts with the two different points, and see which flew straighter. By comparing the angles the bare shafts made with the target, you would have an objective measurement of which combination was better tuned for your bow, as opposed to a subjective feeling that one combination was working better than another.
x2
I also think it wud be a good idea to try bareshafts and a great learning experience because I've never tried it. I've looked at a few videos on the subject and am now tempted to try it.
In the DVD Masters of the Barebow, volume 2 I believe, there is a section by Ken Beck, the former owner of Black Widow Bows, that gives a good introduction to tuning arrows.
QuoteOriginally posted by McDave:
In the DVD Masters of the Barebow, volume 2 I believe, there is a section by Ken Beck, the former owner of Black Widow Bows, that gives a good introduction to tuning arrows.
OK thanks McDave definitely gonna look into it!
I have yet to bareshaft my GT 600's but I did take it a step further with the FOC and went and grabbed three 175 points from my local pro shop and my arrows are flying even better at that weight. My total Arrow weight is now around 540 gns so that's around 275 up front. I'm also experimenting with the GT warrior brand 600s gotta love that name but they are slightly lighter at 5.7 gns per in so total Arrow weight is around 486 but with the same 275 gns up front. Both Arrow setups fly really well after the 30 gn increase up front probably the best that I've seen them fly so far my arrows are still at 32 in but I'm sure if I did need to cut if necessary. All a learning experience and if I lost anything I most certainly can't tell if feel like I gained something with better accuracy down range.
I have yet to bareshaft my GT 600's but I did take it a step further with the FOC and went and grabbed three 175 points from my local pro shop and my arrows are flying even better at that weight. My total Arrow weight is now around 540 gns so that's around 275 up front. I'm also experimenting with the GT warrior brand 600s gotta love that name but they are slightly lighter at 5.7 gns per in so total Arrow weight is around 486 but with the same 275 gns up front. Both Arrow setups fly really well after the 30 gn increase up front probably the best that I've seen them fly so far my arrows are still at 32 in but I'm sure if I did need to cut if necessary. All a learning experience and if I lost anything I most certainly can't tell if feel like I gained something with better accuracy down range.