Whitehorn

Sorry for the geek question...

I know the weight of my arrow and speed out of the bow, does anybody know how to calculate trajectory so I can space my pins out on my sight properly? Just want to figure out how much the pin gaps increase as the distance increases to 60 yards. I realize this will be 'theoretical' but I will certainly double check by shooting to that range.

Thanks in advance and cheers..

Dopler

They have these for adjustablewindage sights like HHA but I have not seen them for regular pin sights?How many pins do you have?What's the farthest pin you want to sight in? Try sighting in your 20 yard pin and then your 60 yard pin and then space out the other pins equally and I think you'll findit will accomplish the same thing as a tape would.

Whitehorn

Thanks Dopler..

I shoot to 60 and the guys at the range gave me the tip that equally spacing your pins will work. But as i understand it the gap increase slightly as the range increases. for example the gap between 20 and 30 is slightly smaller than the gap between 50 and 60.. Just wondering if there is a way to calculate the difference in the gaps, it might be small but I am curious how small..

Cheers.

FSUBIGMAC

Just go out and shoot and adjust each pin accordingly. Seems to be the simple way

OHbowhntr

Yep, there is, it's called going out and SHOOTING!!! Past 50yds, you're gonna be losing over and INCH per yd, even if you're shooting 300fps!!!! In all honesty, I'm not sure how many guy REALLY shoot to 60 yds. Because I've heard a lot of guys CLAIM this, but then they don't really know enough to be shooting that far.

There's no "FORMULA" that will set your pins any better than putting time behind the bow. I shoot to 56yds with my current set-up, and there are about 10" of drop between my 48yd pin and my 56yd pin. At shorter ranges, 24-32yds, I can get away with using my 32yd pin on a 24yd shot and still get a kill, after that, it pin splitting. But to shoot 50-60yds, you have to be VERY precise, I know that at about 52-53yd, I can split my last pins, for a hit on a deer sized game, but if I were target shooting, I'd better know precisely how much hold over under I needed. I'd have a full 16" of drop between 50-60 shooting my rig at 284fps. That means my pin gap should be about 4x what my first pin gap is, but when you factor in the distance it shrinks down a little. The only SERIOUS way to do this is to shoot your bow and adjust to the POI.

Oh by the way, you're right......"The guys at the range are WRONG!!!" if they're saying equal spacing for equal distances.

98Redline

There are a couple of things that you can do to get the "theoretical" pin gaps

1) Use a program like On-Target, Archers Advantage or The Archery Program (TAP)
Based on the information you put in, you can get some very accurate sight tapes out based solely on dead reconing and physics. The better the information in, the more accurate the sight tape out. If you can get a pin set at 20 and one at 60 or longer you can generate an extremely accurate tape that should cover all distances in between.

2) Use a preprinted sight scale. Same principle as above, get a 20 and 60 yard pin sighted dead on, then compare your pin settings to the various scales on the tape. When you find one where the pins line up exactally, all of the intermediate yardages should be correct.
http://www.lancasterarchery.com/prod...oducts_id=2666

In my experience, using these methods is extremely accurate in getting your intermediate yardages set. I have found that as long as my bow is tuned properly, the 20/60 gap method works very well. If you find that given a good 20 and good 60 pin your intermediate yardage pins aren't on the money, then you need to look into something like tuning or fletching contact.


All in all, this is really just a roughing in process. As the others have stated, you still have to shoot every distance to ensure that things are dialed in.

archer 2

Along time ago there was a piece of plastic with lines across it where you shot in say like a 20 yard pin and a sixty yard pin then you took this piece of plastice with the lines and moved it across your top pin till both the long and short distance pins lined up with the lines on piece of plastic then you could set your other pins with other lines that were on the plastic. It actually was quite accurate. I believe Lancasters still sells them.
I went and looked and found them here is the link
http://www.lancasterarchery.com/product_info.php?cPath=39_102&products_id=2666

Whitehorn

Thanks 98 and archer2 for the lancaster link.. That is helpful.. I don't want anybody to think that I am not out there shooting my bow, I am and I am just wanting to learn a little about some of the physics behind this..

Cheers.

bcvd45

Every bow shoots differently. Just because you shoot so fast...with a certain arrow doesn't mean your pins will be in the same place as the next guy. It changes with fletching length and shape. With the rest you are using. Your form. Any little thing can throw everything off. So go out and shoot and figure it out. That way you are comfortable with where they are at.

98Redline

We weren't saying that you simply line up the pins with the speed printed on the scale, but use a sighted in 20 and 60 yard pin as your brackets. If you use the scale that correctly gaps your 20 and 60 yard pins, it doesn't matter if you are shooting 5" helical feathers or 2 1/4" low profile target vanes with points from 75 to 150gr, the gaps for the remaining pins should be correct. At the very least they will get you probably within 2" or so of being on the mark.