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Main Boards => PowWow => Topic started by: the rifleman on December 25, 2013, 12:47:00 PM

Title: wood arrow grouping/tuning?
Post by: the rifleman on December 25, 2013, 12:47:00 PM
I had posted earlier regarding fletching orientation and appreciate the help.  My setup is a Toelke Whip 50# at 28.  I draw 27 and shoot left handed.  This bow is a tack driver with beman mfx 600s and gold tip 1535s using 200 to 275 up front.  I made up some Douglas fir arrows 23/64 w a 5/16 taper at rear spined 45-50 since my bow/form likes weak arrows.  Arrowss are cut to 29 inches to back of taper.
My problem is that the wood arrows consistently group about 8 inches to the right of the carbons --I shoot left handed (which are on the money) at 24 yards.  Normally I think this would mean the arrows were too stiff.  I am using a 160 grain tip and have tried 145 and 190 tips with the same result.  Any advice?
Title: Re: wood arrow grouping/tuning?
Post by: moebow on December 25, 2013, 01:47:00 PM
I'm betting your arrows are weak based on your specifications. (YES, I see you are left handed and that you say your arrows hit to the right.)  Wood arrow spine is based on using 125 grain points and you are over that by one to two spine groups. Plus, you are starting with 45/50# spine shafts which I think is "under" by 1 to 2 groups.  Weak spine and heavier points combine to make your arrow VERY weak in spine.

Add to that, the fact that 23/64" diameter shafts are quite a bit larger than your carbons - so are farther offset from the shelf.

Your Whip is a relatively high performance bow and using 55/60# spine wouldn't be out of line.

Do you have any 125 grain points that you can try on your current arrows (or even some 100s)?

When starting out with wood, stick to 125 points, you CAN use heavier points if you want later but for starting out skip the HFOC that seems so popular with Carbons. You are making a lot of changes in weight and geometry right now from the carbons and wood (although MUCH simpler than carbon) does have it's own set of requirements.

Arne
Title: Re: wood arrow grouping/tuning?
Post by: macbow on December 25, 2013, 01:47:00 PM
It could have something to do with the diameter of the woods being larger.
If you shoot them long enough you might instinctively bring them in.
But I,agree they are acting stiff.
Title: Re: wood arrow grouping/tuning?
Post by: macbow on December 25, 2013, 01:50:00 PM
Follow Moe's advice. He will lead you in the right direction.
Title: Re: wood arrow grouping/tuning?
Post by: Orion on December 25, 2013, 02:26:00 PM
I think you're under spined as well. Are you hearing a click at the shot?  That would indicate the arrow shaft bouncing off the riser.

The larger diameter of your shafts could also be contributing to the problem.  I.e., unless you change your aim, they'll be pointing more to the right than your narrower carbon shafts.

The fact that they're larger diameter than your carbons actually works in favor of a lower spine. The center of the arrow lies further from the center of the bow, producing the same effect as building out the side plate, meaning the arrow has to flex more to clear the riser. In effect, it requires less spine compared to a skinnier arrow.  The problem here seems to be that it's just way  too much less spine.

Dropping down to a 125 grain head will likely help.  Cutting an inch off the length will also help bring them in line, and you don't need two inches of arrow overhanging the riser.  But with a high performance string on a high performance bow, I think you're going to need woodies in the 55#-60# range as well.
Title: Re: wood arrow grouping/tuning?
Post by: Swamp Yankee on December 25, 2013, 03:43:00 PM
Could be a spine issue, but the larger diameter of those wooden shafts is more likely to be the reason.  How do they fly?  If the wood and carbon arrows you have all fly well they may very well be perfectly in tune already.