All - I've been getting a lot of help here lately, but I think I am still on the low end of the education curve. Just trying to move myself up a bit. I am shooting a Bow Tech, pulling close to 70 lbs, 28 inc DL. I have been shooting two types of arrows - Carbon Fury 6075, cut to about 29 1/4. Listed at 10.6 grains. This is Bass Pro's private label. - Gold Tip Whitetail Hunter 5575- cut to 28 1/2. Unsure of the grains. I've decided my spines are a little too stiff. So, was going to go with something about 30 in, in the 9 to 10.5 grain vicnity. Since I don't have a local shop or big box near me, I headed to Wal Mart. Figured I'd pick up a few of whatever they had then decide if I was headed in the right direction. They had their mix of loose arrows. Nearly all in the 10 inch were 5060. They had a couple of 6-pack boxes, one was 5060, the other was higher, maybe 6075. All Carbon Express, and I think at least one of the boxed 6-packs were Pile Drivers. Each of the boxed 6 packs were different poundage and different arrows, I just can't remember what the other box was. Each box specifically said "for 50 to 60lb draw", etc. Now, I had thought a couple of things before looking at these. My assumption was that the number on an arrow, 5060, etc, equated to the draw poundage for that reccomended arrow. I also thought that draw weight corresponded to grain weight. Meaning that a 5060 arrow would have less grainage than a 6075, for example. When I looked at the boxed arrows, it was the opposite. The 5060 arrow was showing something like 9.8 grains while the 6075 were showing grains in the high 8s. Maybe somehow I misread, but I am pretty sure thats what I saw. So, have my assumptions been wrong that a higher poundage specifically needs more grains? I was going to address my spine issue by going to a 30 inch arrow. To that, do I need to get as close to the Carbon Fury 6075s I have been shooting, or will a longer arrow but with potentially lower grain do the trick?
What ever your going to get you need a 350 or some manufacturers a 340 spine arrow. Arrow weight really isn't an issue.
OK, you got me a bit confused. What do those numbers 350 and 340 mean? If I would have seen those numbers, I would have thought that was the weight of the arrow. I would have assumed that was grains X inches. So, for example, to hit 350 at 30 inches would have meant that was a 11.5 GPI arrow. Does it mean something else?
OK - getting there. So, If I see a number like 5575, or 6070, thats not meant to be a draw weight range? Somewhere along the way, I was lead to believe that those numbers were somehow supposed to correspond to draw weight. Now, and remember the source here and that I live a pretty good stretch from a decent store, I was at Wal Mart today. Wal Mart carries many arrows, almost all Carbon Express, but they appear to be for Wal Mart only. They don't appear on Carbon Express' website. They have numbers like 5060, and 6070 and are sold individually. Some have descriptions on the boxes like "for 50-60 lb bows" that correspond to those numbers. I can see where Carbon Express looks like they only have two sizes of shaft, so I could probably safely assume that the 5060 corresponds to a 250 shaft, and the 6070 corresponds to a 350 shaft. But, without knowing that going in, is there some way of knowing? The Gold Tips have me even more confused. I see on their website where they list some arrows with a 4 digit number, like the 5575 that apparently corresponds with a spine of .400, yet other arrows are numbered with a three digit number that corresponds exactly with their spine (300, 400, 500). The ones I got were a special at Bass Pro and also don't appear on their website so I am guess that my 5575 match spines with the ones listed on the Gold Tip site. To think I thought I was getting this figured out Going back to my original problem. I was shooting arrows, the Gold Tips and Carbon Fury, with I think similar spines, but different lengths and grains. So, the Gold Tips were at 28.5 x 8.6 = 245. The Carbon Fury were 29.25x10.6 = 310. My broadheads were hitting a bit left, so based on reading the Easton guide, figured I was having too stiff of a spine. I picked up some of the single Carbon Express today, am guessing be a spine of 350, at 31inches x 10.2 = 325. Not sure if I went the right way, or the wrong way with things.
I am not convinced your arrows are too stiff. What size (weight) head are you shooting? If you are stiff then you can weaken the spine by adding more weight up front...go to a 125 grain head if shooting 100 gr. The more weight up front will try to resist the force of the bow which in turn weakens the spine. According to them it corresponds to draw weight. I know Gold Tip's 5575 (55 lbs to 75lbs) are .400 spine. Although that arrow says 5575... it does not mean it can be shot out of setups between 55-75 lbs without any problems. Its just a guideline so to speak. There are other factors to consider such as arrow length and tip weight to determine the appropiate arrow for your setup. Did you try moving your rest to the right in small increments? As you know...the point of broadhead tuning is to get both the FPs and BHs to impact at the same point on the target. If you arrow is too stiff then you have options. Can't increase bow weight since you're maxed but you could add more weight up front of the arrow or get a longer arrow (last resort IMO). I still don't think you're stiff spined. I'm no expert..not even close. I understand what to do but I'm having one heck of a time Broadhead tuning one of my bows. The Easton Tuning Guide looks good on paper but sometimes tuning sessions don't go as they are "supposed" to. Sometimes the opposite of what they say works. Good luck!
This will put your total arrow (including vanes, knock & insert and assuming 100 grain head) weight around 384 and 449, respectively. (rough estimate) Donnie gave you some good advice above.
Gents - All right, I think I am getting there. I feel like I have been slow on the uptake on this. The reason I was thinking I was having spine issues was due to where the broadheds were hitting, as well as I could see during flight that the arrows weren't flying straight. With the two arrow types I have, the heavier and longer arrows grouped better (Carbon Fury) between broadheads and field points. Plus, and I can't tell you why, I just liked the way they "felt" more than the lighter arrows. I need some new arrows since I have pretty much shoot mine up, so thats why I picked up a few of the singles from Wal Mart. I just want to see how a slightly longer arrow performs before I go invest in a box. Ideally, I would have preffered going with a 30 inch arrow with my DL at 28 and the new arrows ideally would have had the same spine so that the only variable I am changing was length/weight. I am still unclear on how arrow length relates to DL. Some of this is just my method of experimenting and learning.
If you using a fixed blade BH draw your bow and have someone make it at the end of your riser, if your using a expandable make the arrow at the about and inch after your rest. Now measure your arrow with out the nock. That should be your arrow length. Now look at this chart http://www.harvesttimearchery.com/arrow-sizing-chart/ and find the corresponding spine. It looks like you should be either a .400 or .350 After that hind the arrow you want. If your hunting and want to use the same arrow for 3D get the HT-2 Target only get the HT-3 or HT-4 Now whatever the arrow you decide you would like click on it the you can find the spine and it's corresponding weight. If you feel like you need more FOC you can always get weights to add onto the front or add on a wrap.
All right, I think this is going to be the last post on this. I think I am maybe over-analyzing too much. I am going to pick up some new arrows tomorrow. I can't quite decide which ones, but have narrowed it down. It will be - Carbon Express Mutiny - Spine = .404, 8.5 GPI Red-Head CM Blackout -- Bass Pro label, but actually Easton ACC - Spine=.400, 9.6 GPI Red Head Carbon Fury 6075 - Bass Pro Label, but I believe these are actually Carbon Express, maybe Pile Drivers. I was wrong above when I said the spine on these was .400, I finally foun on the BP website where these are .360 and 10.6 GPI. The Mutiny is pretty close to the Gold Tips I was shooting, so I kind of like that. I like that the Black Outs have a bit more weight. I think if I went with either of those, I would increase to about 29.5. Originally, I had some Carbon Fury's that performed better than the Gold Tips, so that was why I liked them. Since I got a total new tune, and new string, the Gold Tips have been flying better. But, I have also shot most of my arrows up so much that I am down to just a couple of each. The Gold Tips certainly fly a lot flatter, but I also understand the trade off there with energy and all that. Anyways, I am probably just more thinking out so loud so to speak. I did have an actual question, and I think it is the last thing I am trying to figure out. A couple of days ago, I had it in my head that the larger the spine number, meaning .400 larger than say .350, equated to a greater draw weight. I see now, actually the opposite is true and typically the larger the spine number, the lower the draw weight. Why is that? Getting my head around what that spine actually means is still not sinking in for me. I may have been reading too much and just confused. Also, and I think I know this, but the spine number has no correspondence to arrow diameter, correct?
I found a link that should explain all you'd like to know about arrow spine AND then some! There is a lot of good info in this. Scroll down to Section 3.7 and it explains all about spine. http://archeryhistory.com/archerytalk/The_Nuts&Bolts_of_Archery.pdf
OK - Disregard at least one question in my last post. I was asking about spine variances, and it finally clicked. Somewhere along the way, I was partially equating the spine number into a diameter. Finally it clicked - the spine number is the amount of flex on the shaft at a set measurement. So, the greater the number, the greater the flex meaning the weaker the spine. So, what is confusing to me, based on charts and reccomendations, is what is happening with my weaker spine Gold Tips. Like I said, right now, they are flying pretty decent hitting a little left of target with broadheads. My Carbon Fury, with a stronger spine are hitting further to the left. Prior to my new string and tune, it was the other way around. Based on chart, and drawing nearly 70 lbs, I would have thought that at .400, I would have too little spine. I may now have a concern that if I increase the length of a .400 spine arrow, I might be going into the too little spine area. I am just in a dilemna. No matter what, I need some new arrows. Was leaning towards either of the above with the .400 but am now second guessing that just cause all the charts say I should be closer to .350. Plus, of the arrows I listed, I like what I read about the others. Seems more logical at this point to go stiffer, then add weight or switch to a 125 grain broadhead (currently using 100s), which was the reccomendation above. Ahh, too late, too much thinking.
