I’m running carbon express 75’s (700 spine) cut to 29” with 125 points on a 35 lb one piece grizzly. I would imagine for you 700’s with lighter points or 600’s with a bit more weight up front would be your best bets. Most 600’s are around the length you want uncut anyways. The axis tend to run stiffer so you may have to tweak your center shot a bit. For stumping and target I like arrows with less foc ( lighter points). They just seem to fly better. Especially my axis traditionals.

 

I'm new to to building arrows and am having a heck of a time trying to figure out what the right combo of spine, point-weight and arrow-length is for me. Obviously the best thing to do is experiment with a bunch of combinations, but I'd like to avoid the cost of buying a ton a equipment I can't use if possible.

I shoot a 35 lb ILF recurve at 29" (actual draw weight and length) that is center cut. I like a couple inches of arrow sticking out past the riser, so I'm looking for arrows in the 30.5" - 31.5" range. I don't actually hunt, but I do stump shooting, field archery, and 3D, so I'm looking at carbon hunting arrows for their durability. Currently, my focus is on Easton axis, just because they're well proven and popular.

Spine charts from Easton and 3Rivers pencil-out to 500 spine, or even 400 spine arrows, with 100gn points. This seems excessive. I've seen videos where folks are shooting 500 spine arrows with 200-300 grains worth of points and inserts like lasers out of 45-55 lb bows.

Then I tried 3Rivers' much more detailed dynamic spine calculator and I'm getting very different results. Here are two setups that theoretically pair well with my 35lb draw weight and arrow length requirements...

• Option 1
  • 30.5"
  • 600 Spine
  • 100gn point
  • 75gn insert
  • 12gn/lb
  • 19.6% foc
• Option 2
  • 31.5"
  • 700 Spine
  • 100gn point
  • 18gn insert
  • 10gn/lb
  • 14.5% foc

These builds are way off from what the simple spine charts recommend. Do these look reasonable for my 35lb bow and arrow length requirements?

I don't know, maybe I'm just going off the deep end trying figure this stuff out. If you've made it this far and have any wisdom or insights please lay it on me.

Thanks.

Yes those are going to be good from the 3 rivers calculator. Ignore most manufacturers charts, except the calculator on the Victory site. I shoot heavier arrows than that for 3d to keep gaps manageable, but 9-10 gpp is what I have been using for field.

 

I know it is annoying to experiment.. but one of the absolute best ways to get nearby is to simply by a selection of arrows in the right general range of what you want at the end of the day. Three rivers will sell you a test kit for most common arrows, as will addictive archery.

I use target arrows since I can spine changes of only 50 from one to another, all the exact same length, mild variations on tip weight, and choose the ones that shoot the best via bare shaft.

Once you get close, some reasonable thumbrules you can use to tweak are below. I built these out by simply checking 3 rivers chart years ago.. I made an error on them, fixed recently.. but they are for "close enough" thinking.

Unless you can shoot groups tighter than ~4-6" at 20yds barebow, it is unlikely you need to worry too excessively about matching spine to bow. Getting close (within ~50-100 on spine) is likely good enough until you can control your aiming, release, form in general. Just use a simple arrow chart and have fun for the first year or two.

~15# draw weight change -> ~100 in spine.

4" change in arrow length~ 100 change in spine or 1"~25 spine

100gr change in tip weight ~100 change in spine or 1gr / 1 spine

not easy to quantify.. if your arrow is a bit stiff increase brace height can bring into tune.

if arrow is a bit stiff you can crank the limbs down a bit to increase draw weight/change arrow release timing. For most of us it is better to chose a comfortable weight and fit arrows to weight, but if your bow is a bit weak for you anyway.. think about it.

 

For the types of archery you mentioned I would stay around 8-9 grains per pound. Especially field archery where you max range is 50 yards. Yes, those heavy arrows make up for a lot of form mistakes but drop like rocks past 30 yards. Another consideration is those limbs. Wood and glass? Carbon/wood? The latter combo can cause an increase in spine.

 

I just went through the tuning process. It's a pita but, the most efficient way is to buy arrows that are in you spine range and different weight points and experiment. For reference, I was shooting 39lbs at 29.5" dl using a 31.5" 700 with standard insert and 100 grain points with a taw of 388. It was weak but completely shootable. The 3Rivers calculator works pretty well if you enter in the information exactly.

 

yeh if you are killing foam n stumps but not meat there is no need for you to hang 180 grains up front, unless you know enough to WANT it there like c m shooter (see post 3) for a specific reason.
100-125 up front & likely - for 35# - & liking a couple extra inches past riser.....I'd probbly start with the .700s at full length & 125s....or 100s......

 

The nbest thing is to buy a few different spines and a lot of different weights - an see what works. The advice above should get you in the ball park.

 

The problem with spine charts is that you can't input all the variables that you may have with your setup. The 3River calculator allows for more of that. Your 2 examples look reasonable. I suspect if you try an Axis 500, 31" which is full length, you would get a reasonable match. The benefit for you with a 500 shaft would be that it would hold up better to hard hits when shooting stumps. I'm sure you could get 600 or even 700 to work, but you won't be able to keep them as long and might need to use lighter points. Consider using Broadhead Adapter Rings with your set up, or footing the shafts for extra strength. For stump shooting you'll want to use a blunt or Judo point. Might want to look at the weights that are available for them and then target that point weight for your set up.

A test kit makes sense for you. You can use the low temperature hot glue to hold the HIT inserts in place for testing. Or push them in with some plastic food wrap to keep them in place. I've had really good results with the low temperature hot melt. Keep your shafts full length and use different point weights to alter the dynamic spine.

 

Thank you for all the considerate suggestions everyone. I think I'm going to just start off with some full length 700s and pick of some 85, 100, and 125 grain points to play around with. If those are too week at full length I'll start taking a quarter inch off at a time. If I blow up too many arrows on stumps or get the urge to hunt I'll look into heavier options with a collar.

Thanks again, this forum is a great resource.

 

For stump shooting you would probably be best to opt for 100g points, mainly because you will find it difficult to find any blunts or Judo heads in anything less than 100g. Your intentions of starting off with full length 700 spine shafts is probably very close to the mark. The lighter GPI of these shafts will give you a flatter trajectory to hit those more distant targets that little bit easier.

My draw length is 28 inches and I shoot bows of around the same weight as you and I find that my 700s with 100g points fly well when cut at around 31 inches even when shot from my 35lb @ 28 inch bows. If you want longer arrows try using full length 600 spine shafts with 100 grain points.

I find it easier to stick with using the one point weight, ie. 100g, for all of my shooting, because it's easier to get used to the trajectory of your arrows if they all behave the same as one another.

You sound like you know a bit about bare shaft tuning, so use those principals when trimming your shafts and you can't go far wrong.

 

Crick,
If I were you I would base my decision on how much you actually stump shoot. That’s going to create the biggest issue for you because of the limited weight offerings in stump shooting points. That being the case you have two good options:
1) Commit to the insert and point weight you want to shoot, use low temp hot melt for your testing, and trim 1/4” at a time off the tip end until you get it tuned.
2) Try aluminums! They are incredibly consistent, easy to work with and tune, super accurate, and plenty durable enough when shooting low poundage. They are also way cheaper and easier to replace when they do get lost or destroyed. You can even tune them with a pipe cutter, hot melt, and a lighter at the range. Easy!

 

Axis 700’s are interestingly longer than 600’s. I can get full-length 700’s to bareshaft just about perfect with 100’s and 125’s up front from mid 30 pound draw weights at ~31” draw length.

 

Some good stuff here. A few additional thoughts. You can make both 600's and 700's work. Since you want the extra length over the shelf, I would opt for 600's, knowing that you may draw a little more as you settle in. You will be looking at a 5/16 shaft or smaller. You can get either a 100gr or 125gr screw in judo tip for stump shooting. You can play with a heavier insert and 100 gr judo or lighter (standard) insert with 125 gr judo tip. Slightly heavier inserts (30-50 gr) also add a little strength to your arrow for stump shooting. Consider fletching length ( 4 or 5") and whether you want a wrap for making arrow much easier to find. I think you could play with 2 600's and 1 700 and find all you need to know and what you like the best. Lots of options. Good luck.