frustration

[STR8SHOOTR]

I Picked up some GT trad .400's to try carbons. I'm having a hell of a time trying to tune through my 52@28 A&H ACS CX Longbow. I'm using 100 grain brass inserts and 125-200 grain points. I draw a touch over 27 between 27.25 to 27.5ish and my brace height is set to 7.25. I cut the arrows to 29.5 to start with erring on the weak side using the 3rivers calculator as to get a general idea. I've cut the shafts down to 28-3/16". I've searched all over trad gang and realize they like a stiff arrow. the bow seems to like the 125 tips at this length but experience and research tells me that this should be too stiff. I have gone all the way up to a 200 grain point. and it also seems to shoot those well. Is it possible to change the point weight that much and still have great flight? could I be getting a fluke false weak with the 125 grain tips that make them seem to bare shaft straight? Some shots I will get an ever so slight stiff reading with the 125-145 and a very slight weak with the 175-200. if you had to pick is it better to be on the slightly stiff side or the slightly weak side? sorry for such a long rant but I wanted to give as much information as possible to whoever decides to provide some insight.

[McDave]

I'm not sure, but it seems likely that the bow you describe is not cut past center, or possibly is not even cut to center.  This type of bow requires a weaker arrow than one cut past center.  I am waking up to the possibility that much of my life I have been ignoring false weak when tuning, and now am careful to be sure that any weak indication I get is a true weak before going any further.  For example, in your case I probably would have started with a 30” shaft, where I would be sure to get a true weak indication, and tune to what I wanted from there.  Like you, I have had situations where the bare shaft has given similar results with a wide range of point weights, and the best explanation of this is false weak.  However, I have also found that when dealing with heavy point weights, say more than 150 grains, increasing point weight seems to not have much effect on tuning, whereas cutting the shaft length does.

As you can see in this example, this recurve that you would think would be cut past center really isn't.  Evidently the thickness of the strike plate is enough that the entire arrow shaft is lying outside of the centerline of the bow, so it has to be tuned much the same as a longbow that is not cut past center.

[STR8SHOOTR]

I agree with you McDave in regards to the point weight. I'm going to check out the centershot when I get a chance. the bow is advertised as cut 3/16" past center. I do know the strike plate is about 1/8" or just under.

[Orion]

What you tried initially should work, but you need to build out the side plate. I've shot .400 Easton Axis shafts with 250 to 300 grains up front out of 50# and 52# ACSs at my 28-inch draw. The A&H ACS riser is cut way past center, at least 3/16 of an inch.The biggest mistake folks make when trying to tune an arrow to an A&H riser is to not build out the side plate. 

My bet is that if you put an arrow on the string and hold the bow vertically and view the arrow from behind, the string will either bisect the shaft or the shaft point will be inside the string.  Need to build out the side plate so the point of the arrow is at least outside/touching the left side of the string (for a right handed shooter) when viewed from behind. The skinnier your arrow, the more you need to build out the side plate.  Then start tuning. Good luck. 

[Roy from Pa]

X's 2 what Orion said..

[McDave]

Before you build out the side plate, test your bow to be sure it really is cut past center. I tested three of my bows, built by different well known bowyers, all of which were supposed to be cut past center, only to find out that none of them were cut much past center, maybe 1/32” or 1/16” at most.  The thickness of the strike plate pushed the arrow shaft out to where the inside edge of the arrow shaft was at center at the strike plate, at best.  At the arrow tip, it was well outside of center.  Of course YMMV (and I hope it does!).  This doesn’t mean that I couldn’t tune it; just had to tune it differently than I would if it were truly cut past center.

[STR8SHOOTR]

I’m going to have to almost agree with McDave in this particular case. It seems that the right edge of the tip of my arrow is barely touching the left side of the string. However after shooting all evening. I’ve come to the conclusion [I’m sure this will change when I start overthinking it again] that the 145 and 175 grain tips seem to shoot the best. I’m probably going to go with the 145 putting me at 10.5 - 10.8 gpp. I appreciate all of the opinions I can get! If anyone has similar specs with the same bow I would like to hear what you’re set up is


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[acedoc]

I Picked up some GT trad .400's to try carbons. I'm having a hell of a time trying to tune through my 52@28 A&H ACS CX Longbow. I'm using 100 grain brass inserts and 125-200 grain points. I draw a touch over 27 between 27.25 to 27.5ish and my brace height is set to 7.25. I cut the arrows to 29.5 to start with erring on the weak side using the 3rivers calculator as to get a general idea. I've cut the shafts down to 28-3/16". I've searched all over trad gang and realize they like a stiff arrow. the bow seems to like the 125 tips at this length but experience and research tells me that this should be too stiff. I have gone all the way up to a 200 grain point. and it also seems to shoot those well. Is it possible to change the point weight that much and still have great flight? could I be getting a fluke false weak with the 125 grain tips that make them seem to bare shaft straight? Some shots I will get an ever so slight stiff reading with the 125-145 and a very slight weak with the 175-200. if you had to pick is it better to be on the slightly stiff side or the slightly weak side? sorry for such a long rant but I wanted to give as much information as possible to whoever decides to provide some insight.

False weak readings are possible. I shoot 100 grain insert and 145 grains points on full length 340 shafts. I can shoot upto 200 grain points out of a toelke ss but the same arrow shows weak on a Belcher ilf.

[The Whittler]

I have a A&H ASC it's 62" 47#@28". I draw 29" and I found the 400 spine worked the best. The 500 spine was weak. Maybe this will help.