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Have no idea why this happened
Had THE strangest thing happen today that I have no explanation for what so ever. A little back ground leading up to todays events. I had to drop my draw weight this year down to 53lbs and seeing I was down to only 10 arrows I felt I should buy more as I never like to have less than 18 arrows on hand. I had for the last 6-7 years shot made by Beman for Cabela's Hunter Stalker Extreme carbon arrows in 340 spine. Based on arrow selection charts and the advice of those more knowledgeable than I, I went with a 400 spine arrow. Could no longer get the Cabela's Stalker Extreme so I went with regular Bemans. Bought a dozen and fletched them using Flex-Feltch 4.18 fletchings using a AZ/EF W/3* helical. Seeing as I was going with different arrows I decided to start from scratch and re-tune my bow. Confirmed my cams were timed, and not leaning. Paper tuned to bullet hole and then used modified French tune until I was center punching a 1/4" rope at 7 and 10 yards then a 5/8" perfectly plumb line at 35 yards 6 of 6 shots. Stopped at 35 as that's all my present skill level allows for. Alternated between vertical and horizontal lines to set my 3 pins at 20, 30, and 40 yards. All this took four rather lengthy range sessions. Today after confirming my pins were still good at 20, 30 and 40 tried my fixed blade BH of choice a100 grain 1-1/8" CD 3 blade Wasp Boss SST. I Spin tested the BH until I confirmed it had zero wobble and I also have and used my Apple Archery spin jig to confirm zero BH wobble. Tried first shot at 30 yards Hit dead perfect horizontally but 3.5- 4" to the left. Shot at 25 then 20 and all hit close enough to the same spot 3.5- 4" to the left the blades over lapped one another. Moved back to 40 yards and again hit a little more left but still had blade over lap. Tried four different arrows after spin testing all, all shot the same. Immediately used modified French tuning to double check my center shot and was again center punching the string with field points all the way to 35 yards. I also have a jig that sits flat against your sight that you align a marker to your string then flip it 180* and use it to check you arrow and sure enough it showed my arrow was centered on my rest.
Then I remembered I used my phone to take pictures of all my micro tuning marks on my rest and sight and used these to confirm nothing had moved. For years I have made a story pole that slips over my cable guide that once I get my bow set I record on it the location of my D-loop, tied on knocks, kisser buttons and other items, it confirmed nothing had moved.
Before I changed anything I consulted a copy I had of how to tune your bow for fixed blade broad heads based on broad head impact. The sheet said if your BH's are impacting to the left among other things to #1-move your rest towards the bow or #2 your arrows might be under spined and try stiffer arrows. Well I had some of my 340 Stalker extreme arrows with and felt it wise to try the simplest fix first, especially one that didn't require me changing anything on my bow.
First shot with the 340 spine arrow at 35 yards hit dead center on the vertical and about 2" high of point of aim, which really surprised me as the 340 arrow is heavier than the 400. Thought one shot doesn't prove anything, but I literally put the next 5 shots with the same BH tipped arrow into a group that measured about 3" from blade edge to blade edge. As expected, was even better at 20 yards. Tried the 400 spine arrow once more and literally right back into the same hole 3.5-4"to the left as before. To double check my double check I shot the 3 other 340 spine Stalker Extreme arrows with BH's all shot very well. Lastly I shot some FPs and they hit consistently 2" low on average of my BHs.
The only thing I can figure based on all the available information is I was under spined . But as I am only shooting 53-54lbs maximum I just don't see how I could've been under spined, but the results don't lie. My DL is 29" and my arrows from front insert to knock valley is 28". I'm not going to argue with success and will remain with 340 spine arrows. I'm guessing the answer is I was under spine in my arrows, as I changed nothing else to fix my BH flight problem. Live and learn.
I too dropped to the low 50 pound range recently. I stuck with my 340s and they shoot great, but I'm using heavier heads, 125 and 150 grains. But I do shoot some 400s out of one bow and they shoot fine with my 100 grain NAP Hellrazors. Same specs as you on that bow, 29" dl and probably 53ish pounds, 28" arrows (Stalker Extremes and Beman ICS Hunters). Is your bow a "hard" cam bow? High IBO?
Long shot guess is the 400 shafts were mislabeled and the are really 509 shafts. Maybe try some ones 400 shaft arrows. Appears to me you have done comprehensive testing and likely missed nothing.
Seems to me there were only a couple posters who told you to switch to 400's. The rest of us told you to stay with the 340's.
It's frustrating for those of us who actually know better to try to over ride the bad advise given by some. While the 400's are not under spined for you according to "the charts", it is just rarely possible to be over spined with any arrow shaft out of your setup. There just is no logical reason to ever go down in spine when changing arrows.
Lesson learned X-man. 12yards I took into account my bow has a hard cam and also I chronographed my bow and took its speed (273fps 10 shot average) in to account, and still every chart I consulted listed 400 spine arrows as being correct. I will never again make this mistake. Why bother asking for advice from those that know more than you if you're not going to heed it. It was this arrow purchase that for the first time I even bothered researching carbon arrows selection, how to pic correct arrow spine and became somewhat educated about what it really means and found out much to my surprise that in the opinion of those who's living is made with carbon arrows that spine consistency has the greatest affect on accuracy VS straightness or weight consistency. Before this I simply read the charts and bought per their recommendation. I originally bought the 340 spine arrows 6-7 years ago based on the advice of a phone conversation with a Cabela's equipment tech because based on my particulars at that time I was borderline between 400 and 340 spine. How ironic I now recall the tech telling me when it comes to carbons when in doubt go to the stiffer spine as in his words, "you almost can not be over spine with carbons". Well my mistake is not a complete loss as I have learned a lesson I will not forget. 340 spine from here on out. Now that I think about it the title of the thread should've been "I have no Idea why I didn't fallow the asked for good advice I was given" Thanks again and my apologies for ignoring good advice.
No apology needed from you. You're not the one who gave the bad advise.
Bowsite offers both good and bad advice. Your challenge is to decipher and learn the difference and who is offering the advice. In time, you will learn who's advice to trust and who's advice to discount.
In my opinion. "x-man" is one of those persons on Bowsite who offers solid advice on equipment and set-up. He offers good advice and wisdom. He has the knowledge and experience to back up his comments.
Not to side step the issue but I don't know how anybody is getting 340 shafts to fly properly out of a 50# bow with light heads, as are being mentioned. I am shooting a 500 grain head at 62# and use 340 shafts. With a 300 grain head I am back to 400 shafts. I find this thread interesting to say the least.
Lever Action, sounds like your arrow selections with BH weights are relative. You have a lot of FOC and Im no expert but that to me seems to be the reason for your results.
Xman is wrong with regards to his "Never over spined theory". The top shooters in the world almost all lean more under spined when they're setting world records. Not to mention the "charts" all error on the side of over spined. Good arrow soft ware like TAP or OT2 is rarely off by much. Glad you got it figured out, but YOU CAN most definitely be OVER SPINED... JS
Funny thing is.. none of those guys are shooting broadheads. Putting wings on the front of your arrow changes everything.
Make a paper airplane and bend the font tip to the side and see what happens. This is what happens to your hunting arrow if it flexes.