TS+ Tuning Advice for Recurve

[mrpenguin]

Hello All!  I have a Robertson Stykbow Vision Falcon IV that I cannot seem to get to tune well.  Here is the deal... The bow is 48@28" which I draw to 28".  It is 58 AMO.  It has a TS+ 3 Trees Flemish String, appears to be 12 strand.  I have Beaver Balls installed, sealskin arrow rest, match stick under that lifting the arrow slightly off the shelf.  The brace height is set to 7 1/2".  I shoot carbon arrows: Easton Axis Full Metal Jacket Dangerous Game, 300 spine, FULL length 32" with 16 gr HIT inserts and either 150 bh or the Muzzy Phantom SS 220 gr bh.  3, 5" feathers on each arrow and the arrows are about 790 grs each.  

That all said, when I first got the bow, I was shooting short 400 spine arrows with 125 gr tips.  BH was 8". The bow had catwhiskers installed, was louder, but the thing grouped beautifully for me.  As the string stretched, the tuning broke down.  I, like a fool, started playing with various other arrows and brace heights to increase speed, plus the whiskers broke off over time, and have not been able to get back to that nice tuning since.  I've tried.

I want to use the heavier DG FMJ arrows so, I need help figuring out how to get that bow to work for me.  Part of this is figuring out just how much weight I am pulling with the TS+ string, then figuring out the brace height adjustment, and finally deciding on arrow length.  So far, they pretty consistently hit right indicating weak spine... but these are 300 spine arrows shot outta 48# bow!!!!!

Any advice would help tremendously!

Erik

[Bowmania]

The deflection of .300 is for a very heavy bow.  Probably 70+ lbs, but I don't have  a chart handy to look that up.  One of my bows is 47 lbs and I draw 29 to shoot a .500 arrow with 280 on the point.  Just started playing with .600 and 200 on the point, but not positive on the results - looks favorable.  PM me Monday and I'll have an answer.

One more thing.   The .500's are cut to 32 inches and the .600's are 30.

Bowmania

[Bill Carlsen]

WOW!!!!!! I shoot 300's out of bows in the 65-70# range with  225  grains up front. I'm not sure what your goal is. Sounds like you want the heaviest arrow you can get but a 300 our of 48#.....I think you are way off track. Right off the bat my first thought was "he needs to be shooting a 500 or 400 spine at the most".  The difference would be in how much weight you put on the front of the arrow. What is it, exactly, that you are trying to achieve?

[JimB]

There are others more qualified to give you specifics but I can tell you,if you have way too stiff an arrow,it can bounce coming around the shelf and give you a false reading and appear to be weak,when it is just the opposite.

I have to believe that those arrows could be nothing but too stiff.I would think even the 400 spines would be too stiff till you got more tip weight on than you had.

I like heavy arrows too but 790 on that bow is super,extra heavy.I would much rather have an arrow lighter,with more FOC.

Arrows may group,but still not be tuned.What you are looking for is bare shaft arrows grouping with your fletched.See bowmaker.net and read about tuning.

I think I would go back to the 400 spine,set up with silencers etc and do some tuning.Get a variety of points,starting at 145 and heavier,using the bowmaker tuning advice.

You should be able to tune the 400's and have a decent weight arrow but a lot of that weight would be forward,which is good.They will be plenty heavy though they might not be adequate for Cape buffalo.

[maineac]

I could be wrong, but I believe that sometimes over strongly spined arrows will show weak.

[**DONOTDELETE**]

Originally posted by maineac:
but I believe that sometimes over strongly spined arrows will show weak.

This is true, try lighter point weight and see what happens. If that doesn't work then try heavier point weight.

[Passthru]

Go with lighter spine 500-600, 100 or 50 grain brass inserts, and/or heavy points to get the overall weight you want.  Your arrows are too stiff.  Stiff arrows can impact the shelf/riser and show weak.

The string isn't the problem.

[cacciatore]

I get several Robertson of all models,they are among the easyest bows to tune.You are way overspined and your Shaft acts like to be too weak.Usually a Vision recurve requires weaker spine than other same poundage bows.You are also using a too heavy arrow for a low poundage bow,my 2 cents,but that is your decision.Really, start once again with a 500 or 600 spined shaft

[mrpenguin]

Gents, Thank you!  That information about heavily overly spined was particularly of interest... I thought by shooting long, long arrows with a heavy tip would take care of the issue... guess I was wrong... I will try going to 500's spine arrows.  I think even the 400's might be too stiff...

[Ragnarok Forge]

Try our the FMJ 500s with a lot of weight up front!  I am shooting 500's with 275 grians up front at 31 inches long out of a 55 lb longbow that I draw to 30.25 inches.  The arrows tune out perfectly and weight 584 grains with 4 - 3inch fletch and a 4 inch tape at the back.  They are giving me 19.8% foc and hit with some authority.  

I suspect the arrows that will tune the best for you will either be 500's or 600's.  Most likely 600's with a lot of weight up front.  That is a good thing.  You can still get a good weight arrow and have extreme FOC which will help with penetration.