Point weight and tuning thoughts...

[Mike Vines]

Originally posted by Prairie Drifter:
 

Originally posted by Mike Vines:
Who knows how to use the calculator that can input my numbers for me to figure out my correct length arrow?

Mike,
 Need your bow stats, ie; type of bow, riser cut,string type and strand #, poundage at your draw and what your draw is. [/b]

I just set a request to get them from Chuck at Two Tracks, unless you already know what his Ambush riser is cut to?

[xtrema312]

I was wrong.  That was a different bow and arrow combo than I shoot now, but it did confirm the change. It was a different version of the calculator I have not uses for a while so has old  data entered.  

I ran my bow and arrow.  I found it was more like 2.4# spine change with the 15 gr.  I also ran that up and down.  It was the same plus and minus the weight.  Then I ran up and down on a 1/2" draw length difference.  That was about the same as the 15 gr. It was maybe about 2.6# spine change. Now that is bow requirement changes not the dynamic spine of the arrow so it is not exactly the same thing.  A change to the arrow changes the arrow, but a change to draw changes what the bow is supposed to need.  

I will try some other arrow combos to see what happens.

[Prairie Drifter]

When you find out I'll run the numbers for you.

[bucksbuouy]

Sorry to come off pompous but lately I have become less of an archer and bow hunter and more of a mad scientist who does freaky experiments with arrow spine, point weight, brace height and the like. To be honest, this stuff does keep me up at night. I need a hobby to get away from my hobby.

If any one has any further questions or needs help with arrow spine and or point weight feel free to pm me.
Jason

[Mike Vines]

Originally posted by Prairie Drifter:
When you find out I'll run the numbers for you.

Allright, here you go...Ambush recurve, 50" tipi to tip, riser cut 1/16" before center, NOT PAST, then side plate brings it to 1/8" BEFORE center, Fast Flight string.  Bow is 49# @ 28", and I draw a true 28".  Right now, I use wood arrows (douglas fir 60/65# full length, 125 grain tips, bohning classic nocks, three 5 1/2" shield or banana feathers.  Total weight is 585 grains)

[xtrema312]

With the calculator I found different shaft lengths with carbon and different spine produce some variables in the lbs of dynamic spine change caused by 15 gr.  Longer shaft act a little different as do stiffer shafts.  I found the greatest change with shorter weaker shaft and lighter points with carbons.  For instance my 30.75” 400 with 275 up front changed 2.4# while a 28" 500 spine with std insert and 125 point up front changed about 3#.  I hit one combo that went 4#.  That is all carbon.  

I tried a 29” 1916 and got 3# change going from std insert with 125 point to 140 point. Tried a 2216 29” with std insert and 175 point and 190 point.  I got 3.8# spine change.  Then I ran the 2216 @ 31” and got 3.2#.

Looks to me like the longer shaft has less change with point weight.  I would have thought it would be the other way around due to leverage.  

I bare shaft for the most part and just play with the calculator.

[xtrema312]

Originally posted by Mike Vines:
 

Originally posted by Prairie Drifter:
When you find out I'll run the numbers for you.

Allright, here you go...Ambush recurve, 50" tipi to tip, riser cut 1/16" before center, NOT PAST, then side plate brings it to 1/8" BEFORE center, Fast Flight string.  Bow is 49# @ 28", and I draw a true 28".  Right now, I use wood arrows (douglas fir 60/65# full length, 125 grain tips, bohning classic nocks, three 5 1/2" shield or banana feathers.  Total weight is 585 grains) [/b]

I have not shot wood for a long time.  

How long is  full length?

Ok wood is all different so need more info. Dia of arrow?  Also it uses AMO spine so not sure how to best enter that.  I will have to do some checking.  Maybe someone shooting wood and using the calculator can better help with the arrow input.

[Mike Vines]

31 1/4" valley of nock to BOP

[xtrema312]

Ok I put in a 10 strand string no silencers.  Figured the shaft at 65# AMO, but no input for dia. of shaft.  Here is what I get so far.

Bow 54.1#
Arrow 49.9#

Add some silencers and you are within maybe 3# so far.

[Steve O]

Originally posted by xtrema312:
I found the greatest change with shorter weaker shaft and lighter points with carbons.  For instance my 30.75” 400 with 275 up front changed 2.4# while a 28" 500 spine with std insert and 125 point up front changed about 3#.  I hit one combo that went 4#.  That is all carbon.  

I tried a 29” 1916 and got 3# change going from std insert with 125 point to 140 point. Tried a 2216 29” with std insert and 175 point and 190 point.  I got 3.8# spine change.  Then I ran the 2216 @ 31” and got 3.2#.

Thanks for doing all that work.

What that tells me is Stu's Calculator is a neat tool to estimate where a good point to   START would be.  Definitely not gospel for small changes.  Field work is   KEY!  

Well, I think this has been a pretty neat discussion.  Is it turkey season yet?      

[Mike Vines]

Originally posted by xtrema312:
Ok I put in a 10 strand string no silencers.  Figured the shaft at 65# AMO, but no input for dia. of shaft.  Here is what I get so far.

Bow 54.1#
Arrow 49.9#

Add some silencers and you are within maybe 3# so far.

I have silencers, and they are 11/32" shafts if that helps any.

[xtrema312]

It showed me that the amount of change is a variable with different arrows. One shooter could see more of a change than another shooter based on arrow set-up.  

Throw in more vs. less feather preference and you get more of a possible level of how much you notice the small change.  

I also think the bow makes a difference.  Everyone says a cut past center bow is more forgiving than a cut out from center bow.  You may see a movement in impact with a cut out from center bow that you wouldn’t see with a cut past center recurve.

I also think FOC plays a factor in what you notice.  When I get HFOC the arrow tends to go where I point it even if the shaft wiggles more out of line in flight.  

So put the extremes of all that together and one person could see a change and another see nothing.  Everyone is right.
   

Let's go shoot something!  

[Steve O]

Mike, you do your personal tuning by PM...you are cluttering up my thread      

   

[Mike Vines]

Originally posted by Steve O:
Mike, you do your personal tuning by PM...you are cluttering up my thread        

     

This is good stuff.  If I keep it up, I too can drive a train in a little while...Oh wait, that's a different kind of engineer.

[xtrema312]

Originally posted by Mike Vines:
 

Originally posted by xtrema312:
Ok I put in a 10 strand string no silencers.  Figured the shaft at 65# AMO, but no input for dia. of shaft.  Here is what I get so far.

Bow 54.1#
Arrow 49.9#

Add some silencers and you are within maybe 3# so far.

I have silencers, and they are 11/32" shafts if that helps any. [/b]

I  had figuredd 11/32 and put in AMO spine of 60# for a variance between bow and arrow of 1.2# not figuring the silencers.  I am just not sure on the AMO vs. ASTM spine.  I think that the  60-65 is AMO.  Just can't recall.  Time to sleep.

[smoke1953]

Just to add another variable for those of us that shoot wood, make sure to spine both sides of your arrows. This might only be an issue in shooting hardwoods where grain can be somewhat inconsistent but I sometimes find a 10# difference in spine from one side to the other in the ash I use. This definitely created flight differences.

[David Yukon]

WOW you guys... I don't know what to say...

[overbo]

SteveO,
Love your story about Mr Snuffer shooting his bareshaft tipped Snuffer.Yes it can be done but there takes quit a bit of TINKERING to a bow and arro combo to do it.I'm sure thru all the years of archery that Roger has under his belt,he knows a thing or 2 about tunning.I would doubt that he can pick up  any alumin. arro and throw a big Snuffer on it and bareshaft shoot it perfectly,as your story suggests.I'm not saying it didn't happen.I'm saying Roger's arro and tip weight was perfectly tuned to that bow and if he had a 145gr Snuffer on that arro,the results could've been  different.
I feel this Stu's thing is very useful for those extremely aggressive bow designs.Some of these bows are so particular in shooting form,to bareshaft tune them can be very challenging.

[Ray Lyon]

Hey Steve, the turkeys up here are confused and strutting because they think it's spring snow melt (our only snow came less than a week ago and it's almost gone).

Anyway.  Your comment about using something like Stu's calculator to get close for someone "new" or someone trying out a shaft that they don't have experience with is pretty spot on.  For me in the end, it still boils down to if I can step back 30 yards and my field points and broadheads are both grouping in the same clump small clump of grass in the sand bank at 30 yards, then I'm good to go.

 Many of the comments above are correct in my opinion when it comes to telling the difference between 15-20 grains of point weight at 20 yards.  However, try shooting that with a low 40's weight bow at 25-30 yards and you'll see a significant difference.

Sometimes I wonder too if before long one of our bowyers is going to invent the compound bow all over again.  We've got "high performace strings" of a myriad of materials (does anybody remember when Kevalar strings came out in the 70's and the latest and greatest before compound bows came on strong??); we've got foam/carbon/concave limbs now,  (does anyone remember the funky recurve limbs with waves I believe it was Carroll Bows) just prior to the compound wave??  Does anyone remember the advertisment for "Dyna-stressed limbs".....new x-7 Easton shafting....Berger buttons (I just acquired one of the originals from early 70's) and on and on.  Some of the old guard (see Fred Asbells article on wood arrows in TBM and Ron LaClair's website on his use and selling of wood arrows again) appears to be bucking this trend.  I think this is a good thing. I've always shot longbows and recurves since 1966.  I did my share of fiddling with carbon arrows for 7 years, but this past fall I switched back to wood arrows and it feels SO good.  Right now I'm prepping a test pack dozen Surewood shafts from Braveheart Archery and I'll dial them in for my Super Shrew and my 71 Super Kodiak.  Yes, "old time" still tinkered and did so by shooting arrows.  Howard Hill used to make up a bunch of arrows, shoot them at long range at a clump of grass and then gather them up in bundles according to where they hit. So yes, there was methodical testing "back in the day" too.  

Maybe I'm reading you wrong, but are you really asking are we moving down the slope to reinventing the compound???? I think tradtional archery is ultimately about getting back to one with your mind and body and enjoying watching the arc of an arrow and getting away from the hi-tech stuff we're used to doing day in and day out (ironic that we're on computers communicating this all).  There are some shortcut's to experience with things like Stu's calculator (I've got a copy on my computer-guilty as charged), but I know ultimately it's the arrows arc and getting back to just shooting that soothes my soul.

[Steve O]

Ray and all,

My intent here was:

1.  To stimulate discussion and get varying opinions.

2.  To state tuning your arrow to your bow is VERY important.

3.  To state none of us is a good enough shot at  30-40 yards to tell if there is a dollar bill worth of weight difference in our points, so don't sweat it!  When one is consistently breaking nocks at 40 yards and has silver dollar sized 6 arrow groups at that  distance, I will believe one CAN see a difference in 15 grains of point weight...

Again, tuning is a GREAT thing!  I think it helps you become a better archer and thus a better bowhunter.  It just strikes me funny when I see some poor guy freaking out because his broadheads are 160g and all he has for field points are 150g...it is almost like they are afraid to shoot them!