We arrived just in time to set up and we shot two lots of three sighters. I needed to adjust my sight a long way to the left before I was happy with it. The round itself was fairly uneventful, and I managed to keep the scoring under control, with only a few minor errors. I managed a total of 338 points, including two tens, which is three points lower than the previous Portsmouth using a club bow. I know that quite a lot of my wayward shots were due to simple variations in anchoring point, or how I was using my back and shoulders, but I think that some of it is due to the arrows I am currently using. No matter how I release, the arrows do not fly on a straight trajectory, but fishtail all the way down the range, which I am convinced is increasing the size of the grouping.
The arrows are on short-term loan until I get my own set and are Easton Platinum Plus XX75, size 1916. They are a little on the long side for me but I don't think that matters too much. What I believe matters most is the size, so I decided to investigate a bit further, having been pointed in the right direction by Martin, followed by some Googling. There are a lot of very technical articles out on the web (who remembers when it was called the Information Superhighway?) and I have referenced one in an earlier post, but it all seems to boil down to getting the right arrows to match both the bow and yourself.
The parameters that are most important are draw length (your measurement) and draw weight (bow measurement) and from this you can use manufacturers' tables to find which of the arrows are most suitable for your bow. My estimated draw length is around 27" and I am currently using a bow with a nominal draw weight of 22lbs at a draw length of 28". To correct for a shorter draw length I need to subtract 2lb for every inch less than 28", giving an actual draw weight of 20lb (you add 2lb per inch over 28" if your draw length is longer). The ideal arrow length is at least one inch longer than your draw length, so my ideal arrow length would be 28".
I downloaded the Easton Target Arrow Selection Chart and looked-up what arrows would suit my bow as it stands now. Although the chart looks complicated, it is packed full of information and is actually fairly easy to use once you have your basic measurements:
- Find the table headed Correct Arrow Length for Target - Field - 3D
- Find the Recurve Bow column on the right-hand side
- Move down the column until your draw weight is in the correct range (top row for my 20lb bow)
- Move left along this row until you get to the figure under the arrow length (28" for me)
- Read off the Group identifier - T2 in my example
- In the lower part of the table, find the section headed with the Group identifier (T2 here). This section lists the arrows that suit your measurements
- Find the model of arrow using the code (key at bottom of table) and read off the size. For Easton Platinum Plus XX75 arrows (code 75), the ideal size for me would be 1716.
The four-figure Easton size codes are a bit odd. The first figure is the outside diameter of the shaft in 64ths of an inch. The second figure is the thickness of the tube material in thousands of an inch. Note that there is a column labelled Spine, which is a measure of the stiffness of an arrow. The lower the number, the stiffer the arrow and higher numbers mean more bendy arrows. Why is this important? With a recurve bow, an arrow must bend to allow it to pass around the riser after release, but is must not bend too much. As draw weight increases, the forces on the arrow increase correspondingly, so a stiffer arrow is needed to resist these forces. If you look at the arrows I am currently using, they are in the last row of Group 6 and, reversing the order we used above, you can see that they are better matched to a bow with a draw weight of between 41 and 45lbs. This tallies with the ideal arrows being narrower than the loan set. I won't be buying arrows until I have settled on a draw weight and bought suitable limbs, but I now know how to find the right match.
Oh, and guess what I found in the case at while putting away the bow? My pressure button! Its absence may have had something to do with my accuracy, but I'm not sure how much. That's what you get for rushing!
Postscript
Although we had been expecting armageddon, the kitchen was fairly tidy when we got home. Only a slightly sticky floor required immediate attention. And the cakes were yummy!
Update Sat 30 March
I urge you to read Martin's comment below. It explains a lot, not least why he is the coach and I am very much the novice....
While the arrows are clearly not right for you, the biggest factor contributing to your relatively poor score this week will be the failure to attach the pressure button. This will have been largely responsible for the left to right inconsistency.
ReplyDeleteThe clue was there in sighters. If your previous settings don't work at all, that is the time to check all the daft equipment related things that can go wrong. (Missing button, limbs upside down, limbs not properly fitted, damaged arrow rest, damaged nocks, bent arrows etc)
Of course the novice tends to assume all inconsistency must be of his own making but do check the kit first if you find you are having to move your sights radically from what worked OK last time out!
And as if to prove the point, the eloquent EA shot a personal best outdoor score on 30th March, this time with his pressure button correctly attached. His handicap was 73, a huge improvement on the 80 he managed on all three previous outings. I expect the trend to continue and that very soon Mrs EA and EA junior will be looking over their shoulders at him catching up fast. (He now has a creditable running handicap of 77 - that's the rounded down average of 80 + 73)
ReplyDelete