(Archery enthusiasts will note some major flaws in my form here. This is an older photo. My left wrist is collapsed and the bow is resting on my palm. My right elbow is high. My knees are nearly locked, I'm standing on my heals, and my rear leg is loaded.)
Everything was wrongA couple of the older guys there commented "have you ever tried shooting a naked shaft?"... Jokes aside... Well, no in fact I had not. These guys know tons and tons and were kindof bored today so decided to help me out. I tried shooting one of their arrows that was unfletched, it hit the bale pointing way off to the left, multiple shots in a row... interesting. But, that was his arrows. I had some arrows that had lost their fletching too, so I went and grabbed one and shot that. Out of 10 shots, 9 hit pointing way left. In case it was my release they both tried shooting... same result. We tried increasing the brace height several times, but got no change. One of them pointed out that my knock height was also wrong, causing the arrow to hit pointing down slightly, we lowered my knock by about 1/8'th of an inch. I shot from sitting for this actually so I was at the same height as the target, making the flattness of the arrow easier to see. Next one of them realized my string was too large for my arrow knocks, he pointed out that this will completely blow the release anyway, even if everything else was right. Still it was shooting left though. I've been shooting 1916 (that's a stiffness of the arrow spine), that's what's in the picture above actually. At a 26" draw. My bow is a really nice 45 lb (at 28" draw) bear recurve. Several people at the range have fawned over the bow actually. It was a luck find on ebay. Mike Dickerson, one of the two guys, then picked up an arrow of his, stripped the fletching off and handed it to me. It was a 1716. I tried shooting that. It flew dead straight, not a wobble, and hit the bail pointing almost perfectly towards me. I shot that several times of 6 shots 5 pointed directly at me. Mike shot it, it was perfect. Then Mike grabbed a carbon arrow 25/45 spine (carbon is rated differently than aluminum). This one had fletching still. I shot it, and it flew like a dream, dead straight and right where I was pointing. Wow! Mike then sat down and made me a new string out of B55 using the Flemish twist technique. The Flemish twist, while being easy to make, also allows adjustment of brace-height by adding or removing twists from the string. I've played with this a little but Mike is incredibly good at it. It would've taken me half a day, it took mike about half an hour. The new one was 8 strands, and thinner strands than the previous. Now the arrows fit smoothly on the string. He set it to the same measurements as we'd set the previous string to as we were fiddling. 8 1/4" brace height 3/8" knock offset. The bow now feels *completely* different. The sound changed, the shock after release that runs through my left hand is totally different. And when I release the 25/45 carbon arrow goes perfectly straight. I shot that one arrow for a while before heading out. I need to make a trip to an archery shop now.
Technical nerdery (skip if you aren't interested in archery of physics)So, for non-archery folks, lets talk about the properties of bows, arrows, and shooters. Here's a list of the interesting properties
- draw length - length from the shooters trigger hand on release to the arrow rest. Obviously this is dependant on the shooter's draw location. If they draw to their chest (yes people do this) it'll be different than if they cheek draw.
- release - this is a very fuzzy property, but people's releases differ even among good shooters, such that the same bow setup may work perfectly for one person but not for another even with all else equal.
- poundage - forwards force applied by the shooter to the string at full draw. Usually this is measured at 28", though not always.
- brace height - distance from the arrow rest or the hand to the string when the bow is strung but not drawn
- speed - this is really a result, but people will talk about a "fast" bow. What they mean is that arrows coming off that bow are going faster than the same arrow would shot off another bow of the same poundage. The energy in an arrow is the integral of the force on the arrow across the entire distance of travel of the string. If the bow only "stacks" at the very end, meaning you pull with 1-10 lbs force until the last inch then you're pulling with 65 lbs force the same will be true as the string pushes the arrow forwards. As a result this would be a "slow" bow. Compounds will actually spike up to say 70 and then have a "let-off" at the end and drop back down to say 50, making it easy to hold full draw. They use cams for this. Recurve and longbows can't do that, so usually a "fast" bow is a bow that stacks quickly and then the curve gets pretty flat early in the draw.
- length - the length of the arrow, what you'd expect
- spine - the stiffness of the arrow, more on this shortly
- shaft weight - the weight of the shaft of the arrow, this impacts where the center of gravity is and the net weight of the arrow.
- tip weight - the weight of the tip on the arrow. Hunters try and match their tip-weight when practicing to the weight of the broadheads they'll shoot when hunting. You don't practice with broadheads cause it messes up the targets and wears out your broadheads. So you practice with the closest thing, a target tip of the same weight.
- fletching - That bit at the back... and yes this is probably last as far as performance is concerned.