Re: crossbows and point of aim
- OK, I think I understand the problem better now. You want to have your
sight picture at a certian distance so that the tip of your bolt is on the
center of the target -- "pointe-blanc" as I believe it is called.
Instead of changing your bolts, which you've said fly and group dandy, why
not change your anchor point? Start with your normal anchor, and put the
tip of the bolt pointe-blanc. You'll miss the center of the target, don't
worry. Just note where your bolts grouped. If you change the distance that
your eye is above the stock, then you will change your sight picture
slightly. If you pivot the stock to compensate, you will change the initial
angle that your bolts are being shot, and thus where they are grouping on
an up-down axis.
For example, if your bolts grouped low, then increase the distance between
your eye and the stock. The tip of the bolt will seem to be below the
center of the target now. Pivot the stock up so that the tip is now
pointe-blanc, while keeping the same distance between your eye and stock.
If you shoot a end of bolts with this new anchor, they will group higher
than your first end.
I *think* this is the same principle that a pellet bow with a peep sight
works on, but I'm not sure.
In theory, if you change your anchor point slightly, you can pointe-blanc
at *any* distance you want with the same set of bolts! This is the
principle behind the stock-peep given in Harmuth's book, _Die Armbrust_.
I use the string and the bottom of my prod as a check that I'm giving a
consist\ent anchor (If the string is not just aligned with the bottom of
the prod, then my anchor is off). Depending on your bow, you might be able
to do something similar.
Another place to check is Josef Alm's book, _Survey of European Crossbows_.
He includes info on various period crossbow shoots.
As a caveat, the only bolts that I ever had pointe-blanc I found quite by
accident. This method seems like it would require alot of trial and error
to find a good anchor point. I'm always in favor of keeping the same
anchor, since especially on timed rounds I need to minimize the amount of
thinking that I do. I need something that I can instinctively snap
comfortably into, no matter how long I've been away from the range, and not
have to pause and think, "Is this my 30 yard anchor or is this the 40 yard
-Lyev Davidovitch, AEthelmearc